Lighting system

ABSTRACT

A lighting system includes a main power source, a power switch, a daylight white color light source driver, an incandescent color light source driver, a first light source unit, and a second light source unit. The power switch includes a first terminal connected to the main power source, a second terminal and a control terminal. The two drivers are connected to the second terminal of the power switch. The first light source unit is driven by the daylight white color light source driver. The second light source unit is driven by the incandescent color light source driver. A switch driving circuit for applying power-saving switch signals is connected to the control terminal of the power switch, and a signal processing circuit for outputting instruction signals is connected to the switch driving circuit.

This application is a Continuation of U.S. Ser. No. 13/554,087, filedJul. 20, 2012, which application is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a lighting system configured to reducethe standby power.

A variation of the present invention relates to an LED lightingapparatus that uses LEDs (light emitting diodes) as the light source.

A variation of the present invention relates to an LED lightingapparatus which uses LEDs (light emitting diodes) as the light sourceand which is configured to be operable by remote control.

A variation of the present invention relates to an LED lightingapparatus including LED chips.

BACKGROUND ART Description of the Related Art

Reduction of use of electric power and power-saving have long beendemanded and are in increasing demand in recent years. In response tosuch a demand, LED lighting using LEDs (light emitting diodes) isincreasingly used mainly at home. LED lighting is superior to lightingusing an incandescent lamp, fluorescent lamp etc. in terms of lowerpower consumption, lower heat generation, longer life, higherreliability and higher response speed.

Patent Document 1 (JP-A-H11-233283) discloses a lighting system, inwhich an AC power source is connected to a lamp via a rectifier, achopper, and an inverter. The chopper is provided with a startingcircuit connected from the rectifier or another rectifier connected tothe AC power source. In this arrangement, when DC power is not suppliedto the chopper controller, the starting circuit is not operational, sothat the standby power reduces.

Patent Document 2 (JP-A-H11-312591) discloses a lighting systemincluding a light source, a lighting device for driving the lightsource, a microcomputer for controlling the state of the light source bycontrolling the lighting device, a receiving part for sending a signalto the microcomputer on receiving a remote control signal, and a signaldetecting part for detecting the signal from the receiving part. Whenthe light source is in the OFF state, the microcomputer is supplied withno DC power and is in a stand-by state, while the receiving part and thesignal detecting part are intermittently supplied with DC power and arein a stand-by state. When the receiving part outputs a signal uponreceiving a remote control signal, DC power is supplied to themicrocomputer in response to the signal outputted from the signaldetecting part, and DC power is continuously supplied to the receivingpart and the signal detecting part.

Patent Document 3 (JP-A-2009-4206) discloses a lighting device, alighting apparatus and a lighting system. A microcomputer forcontrolling the lighting of a discharge lamp is supplied with voltageonly during its operation and when the first switching element is kepton after its operation, and is not supplied with voltage in otherconditions including a stand-by state. With this arrangement, thestand-by power of the lighting device can be kept nearly 0.

Patent Document 4 (JP-A-2007-265818) discloses lighting apparatus whichuses in combination two types of LEDs having a low color temperature anda high color temperature. With this lighting apparatus, light emissionof five colors, i.e., an incandescent color, a warm white color, a whitecolor, a daylight white color and a daylight color can be achieved bychanging the brightness of at least one of the two types of LEDs.

Patent Document 5 (JP-A-2007-122950) discloses a lighting system havinghigh color rendering properties. The lighting system includes two ormore lamps selected from a group consisting of lamps having LEDs onlyand lamps including LEDs and a fluorescent substance to be excited bythe light from the LEDs. The lighting system further includes acontroller for controlling light output from these lamps.

FIG. 12 is a circuit diagram of a conventional lighting systemapplicable to e.g. a ceiling light. A ceiling light is a lightingapparatus to be fixed directly to the ceiling of a room to illuminatethe entire room. To illuminate the entire room by using a singlelighting system, the lighting system needs to have a size and brightnesssufficient for the size of the room.

The lighting system 1200 includes a main power source 11, a controlcircuit 12, a daylight white color light source driver 21, anincandescent color light source driver 22, a first light source unit 31and a second light source unit 32. The control circuit 12 includes anAC/DC converter 13, a transformer 14, a DC/DC converter 15, a signalprocessing circuit 16, and a remote controller receiver 17.

The main power source 11 is e.g. a commercial power source, and its ACvoltage AC1 is e.g. 100V. The AC/DC converter 13, the transformer 14,the DC/DC converter 15 are provided for generating a DC voltage fordriving the signal processing circuit 16. The signal processing circuit16 is connected to a remote controller receiver 17. The remotecontroller receiver 17 responds to a signal transmitted from a remotecontroller transmitter, not shown. The lighting part of the ceilinglight, i.e., the first light source unit 31 and the second light sourceunit 32 are turned on or off in accordance with the signal transmittedto the remote controller receiver 17.

The signal processing circuit 16 supplies a Pulse Width Modulation (PWM)signal to the daylight white color light source driver 21 and theincandescent color light source driver 22.

The daylight white color light source driver 21 and the incandescentcolor light source driver 22 drive the first light source unit 31 havinga color temperature of 5000 K (Kelvin) and the second light source unit32 having a color temperature of 2900 K (Kelvin), respectively. Each ofthe first light source unit 31 and the second light source unit 32includes e.g. a LED or a plurality of LEDs connected in series.

In the conventional lighting system 1200 shown in FIG. 12, the daylightwhite color light source driver 21 and the incandescent color lightsource driver 22 are held in a stand-by state even when the first lightsource unit 31 and the second light source unit 32, i.e., the ceilinglight is in the OFF state. For instance, when the standby power at thecontrol circuit 12 is 0.5 W and the standby power of each of thedaylight white color light source driver 21 and the incandescent colorlight source driver 22 is 0.5 W, the entire lighting system 1200requires a standby power of 1.5 W.

For easier understanding, the lighting system 1200 shown in FIG. 12 isdescribed as including two light source drivers, i.e., the daylightwhite color light source driver 21 and the incandescent color lightsource driver 22. However, a larger number of light source drivers maybe employed, and the standby power increases with the number of thelight source drivers.

Conventionally, a lighting system including a light source such as anincandescent lamp, a fluorescent lamp or the like has been used as alighting system for illuminating a room in a house and so on. In recentyears, however, in accordance with the enhancement in brightness oflight emitting diodes (hereinafter referred to as LEDs), variouslighting systems have been proposed which use LEDs having a smallersize, a lower power consumption and a longer life, instead ofconventional light sources.

For instance, an LED lamp including an LED chip has been proposed as areplacement for an incandescent lamp. Further, an LED lighting system isalso proposed which has the function of adjusting the brightness andchromaticity of the light. For instance, some LED lighting systemsincorporate a plurality of types of LED lamps that emit light ofdifferent color temperatures, so that light of a desired color isobtained by adjusting the brightness of each type of the LED lamps. SuchLED lighting systems are used as a downlight or a ceiling light, forexample.

Among such LED lighting systems, there exists an LED lighting system, asdisclosed in e.g. Patent Document 6 (JP-A-2008-300124), which isconfigured to generate composite light of white LEDs and red LEDs whilesetting the chromaticity of light from the white LEDs to a certainrange, in order to obtain a composite light having a desired colortemperature and high color rendering properties.

However, since such a conventional LED lighting system uses white LEDsof different color temperatures, variations of LEDs are produced in themanufacturing process, resulting in variations in brightness. Suchvariations in brightness of the LEDs lead to non-uniform brightness.Further, when LEDs of different color temperatures are employed, suchvariations in brightness leads to variations in color of compositelight. Thus, before mounting the LEDs, the LEDs are classified into e.g.nine groups based on the combination of brightness and color, and LEDsof a certain group having variations in a limited range are mounted.

However, in the above-described method, measurement needs to beperformed with respect to each of the LEDs for classification intogroups, which needs much time and cost. Further, even when variation issuppressed to a certain degree by the classification, the brightness orchromaticity of the LEDs may not correspond to the brightness orchromaticity satisfactory to the user.

An LED lighting apparatus including an LED chip has been developed as areplacement for a lighting apparatus of a type for attaching e.g. afluorescent lamp. Some of lighting apparatuses to be fixed to a ceilingare configured such that operations such as turning on or off the lightand adjustment of the light can be performed by remote control (SeePatent Document 7 (JP-A-2008-108598), for example).

FIG. 26 schematically illustrates an example of LED lighting apparatusdesigned to be fixed to a ceiling to illuminate a room. The LED lightingapparatus 90 shown in FIG. 26 includes a main body 91 to be fixed to aceiling, and a remote controller 92 for operating the main body 91. Themain body 91 includes a plurality of LED chips and a control unit forcontrolling the lighting of the LED chips in accordance with a signalfrom the remote controller 92. The LED lighting apparatus 90 is designedto allow adjustment of the brightness of the main body 91 and adjustmentof the color of the light emitted from the main body 91. Accordingly,the remote controller 92 includes a button 92 a for brightnessadjustment and a button for color adjustment, in addition to a buttonfor turning on or off the light.

For instance, the LED lighting apparatus 90 can be designed such thatthe brightness of the main body 91 increases by a predetermined one stepwhen the brightness adjustment button 92 a is pressed shorter than 1.25sec. and that the brightness of the main body 91 increases continuouslywhen the brightness adjustment button 92 a is pressed longer than 1.25sec. With this arrangement, the operation to increase the brightnessstep by step and the operation to increase the brightness continuouslycan be performed by using the same button 92 a, which allows the remotecontroller 92 to be made simple.

However, the sense of time is different from person to person, so thateven when the user, who intended to continuously change the brightness,thinks that they have pressed the brightness adjustment button 92 a fora sufficiently long time, the actual pressing time of the brightnessadjustment button 92 a may be shorter than 1.25 sec. In such a case,brightness changes by one step, centrally to the user's intension. Sucha situation where the user cannot operate the lighting apparatus asdesired may cause the user to feel stress.

An LED lighting apparatus including an LED chip has been developed as areplacement for a lighting apparatus of a type for attaching e.g. afluorescent lamp. A lighting apparatus to be fixed to a ceiling isgenerally called a ceiling light. For instance, Patent Document 8(JP-A-2008-300203) discloses a conventional LED lighting apparatus usedas a ceiling light.

FIG. 47 shows an example of ceiling light. The LED lighting apparatus900 shown in the figure is in the form of a thin disc as a whole andused as fixed to a ceiling. The LED lighting apparatus 900 includes aplurality of LED chips 910D, a plurality of substrates 920D, and a cover930 covering the LED chips 910D. As shown in FIG. 47, each substrate920D is curved along the circumferential direction. Each substrate 920Dis prepared by cutting a rectangular substrate material. As comparedwith cutting rectangular substrates out of a rectangular substratematerial, cutting substrates having a curved shape out of a rectangularsubstrate provides a smaller number of substrates. Moreover, when anyfailure occurs, the substrate 920D needs to be disposed of, which leadsto waste and an increase in the manufacturing cost.

Moreover, when rectangular substrates are simply arranged in a circularregion, the LED chip 910D cannot be arranged uniformly, so that part ofthe LED lighting apparatus 900 may become dark.

An LED lighting apparatus including an LED chip has been developed as areplacement for a lighting apparatus of a type for attaching e.g. afluorescent lamp. A lighting apparatus to be fixed to a ceiling isgenerally called a ceiling light.

FIG. 65 shows an example of conventional LED lighting apparatus for useas a ceiling light (see Patent Document 8, for example). The LEDlighting apparatus 900 shown in the figure has a thin circular shape asa whole and is used as attached to a ceiling 800. The LED lightingapparatus 900 includes a plurality of light source units 910, areflective surface 920 and a cover 930. The light source units 910incorporate LED chips (not shown) and are arranged on a circle. Thereflective surface 920 is a surface of a metal plate that is paintedwhite, for example. As shown in the figure, the reflective surface 920is arranged on the radially inner side of the light source units 910arranged on a circle. Light from the light source units 910 is reflectedby the reflective surface 920 to travel downward in the figure. Thecover 930 is made of e.g. a resin material that transmits light whilediffusing, and hence, transmits the light, reflected by the reflectivesurface 920, downward in the figure while diffusing.

The LED lighting apparatus 900 is designed such that light is emittedthrough the cover 930 covering the light source units 910 and thereflective surface 920. Thus, the LED lighting apparatus 900 as a wholehas a relatively large thickness. To enhance the appearance of a livingroom or the like to which the LED lighting apparatus 900 is installed,further thickness reduction of the LED lighting apparatus 900 isdemanded. In addition to the LED lighting apparatus 900 used as aceiling light to be fixed to a ceiling 800, an LED lighting apparatus ofa type called a pendant light is also demanded which emits light towardthe floor from a position spaced a certain distance from the ceiling.

An LED lighting apparatus including an LED chip has been developed as areplacement for a lighting apparatus of a type for attaching e.g. afluorescent lamp. A lighting apparatus to be fixed to a ceiling isgenerally called a ceiling light.

FIG. 77 shows an example of conventional LED lighting apparatus for useas a ceiling light (see Patent Document 8, for example). The LEDlighting apparatus 900 shown in the figure is used as attached to aceiling 800. The LED lighting apparatus 900 includes a plurality oflight source units 910, a reflective surface 920 and a cover 930. Thelight source units 910 incorporate LED chips (not shown). The reflectivesurface 920 is a surface of a metal plate that is painted white, forexample. Light from the light source units 910 is reflected by thereflective surface 920 to travel downward in the figure. The cover 930is made of e.g. a resin material that transmits light while diffusing,and hence, transmits the light, reflected by the reflective surface 920,downward in the figure while diffusing. The LED lighting apparatus 900is designed to achieve both the good appearance along a ceiling and theuniform illumination of a room.

However, reduction in thickness of the LED lighting apparatus 900accompanies increased limitation on the shape of the reflective surface920. Such limitation hinders uniform illumination by the LED lightingapparatus 900.

An LED lighting apparatus including an LED chip has been developed as areplacement for a lighting apparatus of a type for attaching e.g. afluorescent lamp. A lighting apparatus to be fixed to a ceiling isgenerally called a ceiling light. For instance, Patent Document 8discloses an LED lighting apparatus for use as a ceiling light.

FIG. 88 shows an example of ceiling light. The LED lighting apparatus900 shown in the figure has a thin circular shape as a whole and used asfixed to a ceiling. The LED lighting apparatus 900 includes a pluralityof LED substrates 910G, a plurality of LED chips 920G mounted on each ofthe LED substrates 910G, and a cover 930 covering the LED substrates910G. The plurality of LED substrates 910G are arranged such that theedges of each LED substrate face edges of adjacent LED substrates,thereby forming a ring-like shape. A pair of connectors 940, 950 areprovided at facing edges of adjacent LED substrates 910G.

To each of the connectors 940, 950 is connected a connection end of awiring 960, which is made of a single core wire. The connectors 940, 950of each pair are arranged such that the connection portions face eachother. Thus, both the connection direction (first connection direction)of a connection end to the connector 940 and the connection direction(second connection direction) of a connection end to the connector 950are along the circumferential direction n1 of the LED substrates 910G.To achieve proper connection to each connector 940, 950, the wiring 960is made to have a certain margin and curved along the LED substrate910G, as shown in FIG. 88.

However, according to the above-described structure in which theconnectors 940 and 950 face each other, the wiring 960 rotates easilywhen rotation moment is exerted between the connectors 940, 950 and thewiring 960. Thus, in using the LED lighting apparatus 900, the curvedportion of the wiring 960 may move and hinder the progress of the lightfrom the LED chips 920G, making part of the LED lighting apparatus 900dark.

Patent Document 1: JP-A-H11-233283

Patent Document 2: JP-A-H11-312591

Patent Document 3: JP-A-2009-4206

Patent Document 4: JP-A-2007-265818

Patent Document 5: JP-A-2007-122950

Patent Document 6: JP-A-2008-300124

Patent Document 7: JP-A-2008-108598

Patent Document 8: JP-A-2008-300203

SUMMARY OF THE INVENTION

The present invention provides a lighting system configured to reducethe standby power. In particular, the invention provides a lightingsystem configured to reduce the standby power even when the system isconstructed as a high power comsumption type with a number of lightsource drivers.

A variation of the present invention, which is conceived to solve theabove-described problem, aims to provide an LED lighting system which isconfigured to correct variations in brightness or chromaticity of LEDsafter the mounting and which eliminates the need for strictly correctingsuch variations.

A variation of the present invention, which is conceived to solve theabove-described problem, aims to provide an LED lighting apparatus thatoperates precisely in accordance with the user's intention.

A variation of the present invention, which is conceived to solve theabove-described problem, aims to provide an LED lighting apparatus thatcan achieve uniform illumination while using rectangular substrates.

A variation of the present invention, which is conceived to solve theabove-described problem, aims to provide an LED lighting apparatus thatcan achieve thickness reduction, and an LED lighting apparatus that canbe used as a ceiling light or a pendant light.

A variation of the present invention, which is conceived to solve theabove-described problem, aims to provide an LED lighting apparatus thatcan achieve more uniform illumination and good appearance.

A variation of the present invention, which is conceived to solve theabove-described problem, aims to provide an LED lighting apparatus thatis suitable for more uniform illumination.

A lighting system according to the present invention comprises: a mainpower source; a power switch including a first terminal, a secondterminal and a control terminal, the first terminal being connected tothe main power source; a light source driver connected to the secondterminal of the power switch; a light source unit driven by the lightsource driver; and a signal processing circuit for supplying to thecontrol terminal of the power switch a switching signal for electricallyconnecting or disconnecting the power switch.

Preferably, in the lighting system according to the present invention,the light source driver includes a first light source driver and asecond light source driver, the light source unit includes a first lightsource unit and a second light source unit, and the first light sourcedriver and the second light source driver drive the first light sourceunit and the second light source unit, respectively.

Preferably, in the lighting system according to the present invention,the first light source driver and the second light source driver arecommonly connected to the second terminal of the power switch.

Preferably, in the lighting system according to the present invention,the first light source unit and the second light source unit include atleast two white light sources of colors selected from a daylight color,a daylight white color, a white color, a warm white color and anincandescent color.

Preferably, in the lighting system according to the present invention,the first light source unit comprises an LED for a daylight white color,whereas the second light source unit comprises an LED for anincandescent color.

Preferably, in the lighting system according to the present invention,the power switch comprises a mechanical relay or a solid state relay.

Preferably, in the lighting system according to the present invention,the light source driver is driven by a pulse width modulation (PWM)signal outputted from the signal processing circuit.

Another lighting system according to the present invention comprises: anAC power source; a power switch including a first terminal, a secondterminal and a control terminal, the first terminal being connected tothe AC power source; an AC/DC converter connected to the second terminalof the power switch; a smoothing capacitor that is connected to anoutput of the AC/DC converter, includes a first terminal and a secondterminal, and generates a first power source voltage between the firstterminal and the second terminal; a chopper circuit to which the firstpower source voltage generated by the smoothing capacitor is inputtedand which generates a second DC voltage lower than the first powersource voltage; and a light source unit to which the second DC voltageis supplied and which includes a plurality of LEDs connected to eachother. The AC/DC converter is electrically connected or disconnectedbased on a switching signal applied to the control terminal of the powerswitch.

In the above-described structure, the power switch is arranged betweenthe main power source and light source drivers having a relatively largepower consumption. With this arrangement, by disconnecting the powerswitch, power consumption at the light source driver and the lightsource unit connected to the light source driver is stopped, which leadsto standby power reduction and power saving of the entire lightingsystem.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram of a lighting system according to a firstembodiment of the present invention;

FIG. 2 shows a lighting system according to a second embodiment of thepresent invention;

FIG. 3 is a circuit diagram of a light source driver of the presentinvention;

FIG. 4 is a circuit diagram of a switch driving circuit of the presentinvention;

FIG. 5 shows another example of a circuit structure of a power switch ofthe present invention;

FIG. 6 shows another example of a circuit structure of a power switch ofthe present invention;

FIG. 7 is a timing chart of electrically connecting or disconnecting apower source driver according to the present invention;

FIG. 8 shows a lighting system according to a third embodiment of thepresent invention;

FIG. 9 shows a lighting system according to a fourth embodiment of thepresent invention;

FIG. 10 shows a lighting system according to a fifth embodiment of thepresent invention;

FIG. 11 is a circuit diagram of a first LED lighting unit according tothird through fifth embodiments of the present invention;

FIG. 12 is a circuit diagram of a conventional lighting system;

FIG. 13 illustrates a chromaticity/brightness control map representing arated output range of an LED lighting system of 1B embodiment accordingto a variation of the present invention;

FIGS. 14A-14D show examples of patterns for changing the rated outputrange represented by the chromaticity/brightness control map;

FIGS. 15A and 15B show duty ratios of PWM signals corresponding to themaximum and minimum points and the rated output range of thechromaticity/brightness control map shown in FIG. 13;

FIG. 16 shows an example of arrangement of daylight white color LEDs andincandescent color LEDs in the LED lighting apparatus according to avariation of the present invention;

FIG. 17 shows a time chart of lighting operation and putting-outoperation by a conventional LED lighting apparatus;

FIG. 18 shows a time chart of lighting operation and putting-outoperation by the LED lighting apparatus according to a variation of thepresent invention;

FIG. 19 shows a time chart of lighting operation and putting-outoperation by the LED lighting apparatus according to a variation of thepresent invention;

FIG. 20 is a block diagram showing an example of structure of the LEDlighting apparatus according to a variation of the present invention;

FIG. 21 shows examples of PWM signals for daylight white color LEDs andincandescent color LEDs of the LED lighting apparatus according to avariation of the present invention;

FIG. 22 shows an LED lighting apparatus of 1C embodiment according to avariation of the present invent ion;

FIG. 23 is a schematic structural diagram of the main body shown in FIG.22;

FIG. 24 is an enlarged plan view of the remote controller shown in FIG.22;

FIG. 25 shows an example of controlling process in the LED lightingapparatus shown in FIG. 22;

FIG. 26 shows an example of conventional LED lighting apparatus;

FIG. 27 is a plan view showing an LED lighting apparatus of 1Dembodiment according to a variation of the present invention;

FIG. 28 is a side view of the LED lighting apparatus shown in FIG. 27;

FIG. 29 is a bottom view of the LED lighting apparatus shown in FIG. 27;

FIG. 30 is a sectional view taken along lines IV-TV in FIG. 29;

FIG. 31 is an enlarged side view of the support unit shown in FIG. 30;

FIG. 32 is an enlarged perspective view showing a principal portion ofthe support unit shown in FIG. 31;

FIG. 33 is a sectional view taken along lines VII-VII in FIG. 32;

FIG. 34 is a sectional view taken along lines VIII-VIII in FIG. 32;

FIG. 35 is a view for describing the conduction portion shown in 33;

FIG. 36 is a view for describing the substrate shown in FIG. 32;

FIG. 37 is a view for describing a substrate different from that shownin FIG. 36;

FIG. 38 is a view for describing a spacer that can be provided insteadof the conduction portion shown in FIG. 33;

FIG. 39 is a sectional view showing an LED lighting apparatus of 2Dembodiment according to a variation of the present invention;

FIG. 40 is a schematic bottom view of the LED lighting apparatus shownin FIG. 39;

FIG. 41 is a schematic side view of the LED lighting apparatus shown inFIG. 39;

FIG. 42 shows a cross section perpendicular to a circumferentialdirection of the support unit shown in FIG. 39;

FIG. 43 is a schematic bottom view showing another example of the LEDlighting apparatus shown in FIG. 39;

FIG. 44 is a schematic bottom view showing another example of the LEDlighting apparatus shown in FIG. 39;

FIG. 45 is a schematic bottom view showing another example of the LEDlighting apparatus shown in FIG. 39;

FIG. 46 is a sectional view showing an LED lighting apparatus of 3Dembodiment according to a variation of the present invention;

FIG. 47 is a sectional view showing an example of conventional LEDlighting apparatus;

FIG. 48 is a front view showing an LED lighting apparatus of 1Eembodiment according to a variation of the present invention;

FIG. 49 is a sectional view taken along lines II-II in FIG. 48;

FIG. 50 is a sectional view showing an example of LED module used forthe LED lighting apparatus of FIG. 48;

FIG. 51 is a sectional view showing another example of use of the LEDlighting apparatus shown in FIG. 48;

FIG. 52 is an exploded sectional view of the LED lighting apparatusshown in FIG. 48;

FIG. 53 is an exploded sectional view for describing the assembling ofthe LED lighting apparatus for use as shown in FIG. 51;

FIG. 54 is an enlarged sectional view showing a principal portion of avariation of a diffusion reflection plate of the LED lighting apparatusshown in FIG. 48;

FIG. 55 is an enlarged sectional view showing a principal portion ofanother variation of a diffusion reflection plate of the LED lightingapparatus shown in FIG. 48;

FIG. 56 is an enlarged sectional view showing a principal portion ofanother variation of a diffusion reflection plate of the LED lightingapparatus shown in FIG. 48;

FIG. 57 is an enlarged sectional view showing a principal portion ofanother variation of a diffusion reflection plate of the LED lightingapparatus shown in FIG. 48;

FIG. 58 is a sectional view showing an LED lighting apparatus of 2Eembodiment according to a variation of the present invention;

FIG. 59 is sectional view showing a principal portion of the LEDlighting apparatus shown in FIG. 58;

FIG. 60 is a sectional view showing another example of LED lightingapparatus of 2E embodiment according to a variation of the presentinvention;

FIG. 61 is an enlarged sectional view showing a principal portion ofanother example of LED lighting apparatus of 2E embodiment according toa variation of the present invention;

FIG. 62 is an enlarged sectional view showing a principal portion ofanother example of LED lighting apparatus of 2E embodiment according toa variation of the present invention;

FIG. 63 is an enlarged sectional view showing a principal portion ofanother example of LED lighting apparatus of 2E embodiment according toa variation of the present invention;

FIG. 64 is an enlarged sectional view showing a principal portion ofanother example of LED lighting apparatus of 2E embodiment according toa variation of the present invention;

FIG. 65 is a sectional view showing an example of conventional LEDlighting apparatus;

FIG. 66 is a plan view showing an LED lighting apparatus of 1Fembodiment according to a variation of the present invention;

FIG. 67 is a side view of the LED lighting apparatus shown in FIG. 66;

FIG. 68 is a bottom view of the LED lighting apparatus shown in FIG. 66;

FIG. 69 is a sectional view taken along lines 1V-TV in FIG. 66;

FIG. 70 is a plan view of the LED lighting apparatus shown in FIG. 66,with a cover removed;

FIG. 71 is a sectional view showing an example of LED module used forthe LED lighting apparatus of FIG. 66;

FIG. 72 is a sectional view corresponding to FIG. 69, showing an LEDlighting apparatus of 2F embodiment according to a variation of thepresent invention;

FIG. 73 is a plan view of the LED lighting apparatus shown in FIG. 72,with a cover removed;

FIG. 74 is a vertical sectional view along a circumferential directionof an LED mount region of the LED lighting apparatus shown in FIG. 72;

FIG. 75 is a sectional view corresponding to FIG. 69, showing an LEDlighting apparatus of 3F embodiment according to a variation of thepresent invention;

FIG. 76 is a vertical sectional view along a circumferential directionof an LED mount region of the LED lighting apparatus shown in FIG. 75;

FIG. 77 is a sectional view showing an example of conventional LEDlighting apparatus;

FIG. 78 is a plan view showing an LED lighting apparatus of 1Gembodiment according to a variation of the present invention;

FIG. 79 is a side view of the LED lighting apparatus shown in FIG. 78;

FIG. 80 is a bottom view of the LED lighting apparatus shown in FIG. 78;

FIG. 81 is a sectional view taken along lines IV-IV in FIG. 78;

FIG. 82 is a plan view of the LED lighting apparatus shown in FIG. 78,with a cover removed;

FIG. 83 is an enlarged view of a principal portion of FIG. 82;

FIG. 84 shows part of a partition as developed as viewed in a radialdirection of an LED substrate;

FIG. 85 is a sectional view showing an example of LED module used forthe LED lighting apparatus of FIG. 78;

FIG. 86 is a sectional view corresponding to FIG. 81, showing aprincipal portion of another example of the LED lighting apparatusaccording to a variation of the present invention;

FIG. 87 is a plan view corresponding to FIG. 83, showing a principalportion of another example of the LED lighting apparatus according to avariation of the present invention; and

FIG. 88 is a plan view showing an example of conventional LED lightingapparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

FIG. 1 shows a lighting system according to the present invention. Thelighting system 100 differs from the conventional lighting system 1200shown in FIG. 12 in that the lighting system 100 includes a switchdriving circuit 18 and a power switch 19. The switch driving circuit 18is arranged between a signal processing circuit 16 and the power switch19. The switch driving circuit 18 responds to an instruction signal S16outputted from the signal processing circuit 16.

For the power switch 19, a mechanical relay or a solid state relay canbe used. Examples of known mechanical relay include an electromagneticrelay. Examples of known solid state relay include phototriac relay anda Photo-MOS relay. Either type of relay can be used as long as it issuitable for turning on and off a relatively high voltage of AC 100 V orhigher.

To stop the operation of the daylight white color light source driver 21and the incandescent color light source driver 22, i.e., to shut off(turn off) the first light source unit 31 and the second light sourceunit 32, the power switch 19 is made open, i.e., the first terminal 191and the second terminal 192 of the power switch 19 are disconnected.FIG. 1 shows the switch-open state, i.e., the state where the firstterminal 191 and the second terminal 192 are disconnected. Selectionbetween connection and disconnection of the first terminal 191 and thesecond terminal 192 is made in accordance with a signal transmitted froma remote controller transmitter, not shown, and received by the remotecontroller receiver 17.

The instruction signal S16 outputted from the signal processing circuit16 and the power-saving switch signal S18 outputted from the switchdriving circuit 18 do not necessarily need to have the same polarity.That is, when the instruction signal S16 is at a high level, thepower-saving switch signal S18 does not necessarily need to be at a highlevel. When the instruction signal S16 is at a low level, thepower-saving switch signal S18 does not necessarily need to be at a lowlevel. This is because the polarity of the power-saving switch signalS18 to be outputted from the switch driving circuit 18 can be set toeither a high level or a low level, regardless of the polarity of theinstruction signal S16. Further, the power switch 19 can be brought intoeither a conduction state or a non-conduction state, regardless of thepolarity of the signal outputted from the switch driving circuit 18.

To the first terminal 191 of the power switch 19 is applied an ACvoltage AC1, which is e.g. a commercial power source. When the firstterminal 191 and the second terminal 192 are connected, i.e.,short-circuited, the AC voltage AC1 is supplied to the second terminal192 as well. The AC voltage AC1 is supplied to both the daylight whitecolor light source driver 21 and the incandescent color light sourcedriver 22.

In addition to the AC voltage AC1, PWM signals Spwm 1, Spwm 2 aresupplied from the signal processing circuit 16 to the daylight whitecolor light source driver 21 and the incandescent color light sourcedriver 22. Specifically, PWM signals are supplied to the daylight whitecolor light source driver 21 and to the incandescent color light sourcedriver 22 via a signal line 161 and a signal line 162, respectively. Itis preferable that the PWM signals used in the present invention have afrequency of 500 Hz or higher.

The first light source unit 31 and the second light source unit 32 areturned on by the daylight white color light source driver 21 and theincandescent color light source driver 22, respectively, by e.g. dutycontrol.

Generally, in a lighting system, duty control is one of methods tocontrol the brightness of e.g. LEDs. Of course, instead of employing theduty control, the brightness of an LED can be adjusted by changing themagnitude of the forward current flowing to the LED. With such a method,however, the brightness changes greatly even with a small change in theforward current, so that fine adjustment of the brightness is difficult.For this reason, the duty control is employed which causes an LED toblink quickly, with the current flowing to the LED kept constant.

LEDs can be used for the first light source unit 31 and the second lightsource unit 32. Instead of LEDs, use may be made of organic EL (ElectroLuminescence) devices, high intensity discharge (HID) lamps, fluorescentlamps, electric lamps, for example.

In the lighting system 100 shown in FIG. 1, the first light source unit31 and the second light source unit 32 emit light of the daylight whitecolor and light of the incandescent color, respectively, which aredefined in JIS standard Z9112, and each color of light is adjustedindependently to obtain the brightness between these two.

The feature of the lighting system of the present invention shown inFIG. 1 is summarized as follows: The lighting system 100 includes a mainpower source 11, and a power switch 19 including a first terminal 191, asecond terminal 192 and a control terminal 193. The first terminal 191of the power switch 19 is connected to the main power source 11. Thelighting system 100 further includes a light source driver 21 (22)connected to the second terminal 192 of the power switch 19, a lightsource unit 31 (32) driven by the light source driver 21(22), and asignal processing circuit 16 for supplying a power-saving switch signalS18 for turning on or off the power switch 19 to the control terminal193 of the power switch 19.

In the lighting system 100 shown in FIG. 1, a first light source drivercorresponding to the daylight white color light source driver 21 and asecond light source driver corresponding to the incandescent color lightsource driver 22 are provided as the light source driver. Further, thefirst light source unit 31 and the second light source unit 32 areprovided as the light source unit. The first light source driver 21 andthe second light source driver 22 drive the first light source unit 31and the second light source unit 32, respectively. According to thiscircuit structure, the power source voltage for the first light sourcedriver and the second light source driver are commonly supplied from thesecond terminal 192 side of the power switch 19. Thus, by controllingthe power switch 19, power source voltage supply to these two driverscan be started or shut off at the same time, which is effective forreducing the standby power.

Second Embodiment

FIG. 2 shows a second embodiment of a lighting system according to thepresent invention. The second embodiment differs from the firstembodiment shown in FIG. 1 in that the second embodiment includes alarger number of light source units and light source drivers. Thus, thesecond embodiment has larger power consumption at the light sourcedrivers than the first embodiment.

As shown in FIG. 2, the lighting system of the second embodimentincludes a daylight color light source driver 23, a white color lightsource driver 24, and a warm white color light source driver 25, inaddition to the daylight white color light source driver 21 and theincandescent color light source driver 22 employed in the firstembodiment.

Further, the lighting system of the second embodiment includes a thirdlight source unit 33, a fourth light source unit 34, and a fifth lightsource unit 35, in addition to the first light source unit 31 and thesecond light source unit 32 employed in the first embodiment.

The second embodiment shown in FIG. 2 is a lighting system conceived inview of the Japanese Industrial Standards (JIS) Z9112. That is, JISZ9112 defines five white light colors, i.e., a daylight color, adaylight white color, a white color, a warm white color, and anincandescent color. The second embodiment includes five light sourceunits for emitting these five colors of light, and five light sourcedrivers for individually driving the five light source units. The colortemperatures of the daylight color, the daylight white color, the whitecolor, the warm white color and the incandescent color are 6500 K(Kelvin), 5000 K, 4200 K, 3500 K, and 2900 K, respectively.

Similarly to the lighting system shown in FIG. 1, when the standby powerat the control circuit 12 is 0.5 W and the standby power at each of thelight source drivers is 0.5 W, the entire lighting system 200 consumesthe power of 3.0 W. Accordingly, the second embodiment seems to requiretwice the standby power of the first embodiment shown in FIG. 1.

According to the present invention, however, the power switch 19 canshut off the five light source drivers at the same time, so that onlythe standby power for the control circuit 12 is necessary. Thus, thestandby power is equal to that of the lighting system 100 shown inFIG. 1. That is, in the lighting system according to the presentinvention, the standby power is required only at the control circuit 12regardless of the number of the light source drivers, and hence providesgreater advantage as the system is made larger and the electric power ishigher.

FIG. 3 more specifically shows the power switch 19, the daylight whitecolor light source driver 21, and the first light source unit 31 shownin FIGS. 1 and 2. Although FIG. 3 illustrates the daylight white colorlight source driver 21 and the first light source unit 31 as examplesfor easier understanding, this structure is also applicable to thecircuit structure comprising the power switch 19, the incandescent colorlight source driver 22, and the second light source unit 32. Further,the circuit shown in FIG. 3 is also applicable to the circuit structureshown in FIG. 2 which comprises the power switch 19, the daylight colorlight source driver 23 and the third light source unit 33, the circuitstructure comprising the power switch 19, the white color light sourcedriver 24 and the fourth light source unit 34, or the circuit structurecomprising the power switch 19, the warm white color light source driver25, and the fifth light source unit 35.

Although the first light source unit 31 is illustrated in FIG. 3 asincluding four LEDs LED1-LED4 for the convenience of drawing, the numberof LEDs is not limited to four.

In FIG. 3, the main power source 11 supplies AC voltage AC1 to the firstterminal 191 of the power switch 19. To the second terminal 192 of thepower switch 19 is connected a diode bridge circuit DB. The diode bridgecircuit DB consists of four rectifier diodes D1-D4. Such a structure iswell known to those skilled in the art as a full-wave rectificationdiode bridge circuit. In this way, the power switch 19 is provided noton the downstream of the diode bridge circuit DB but directly downstreamof the main power source 11. In other words, the power switch 19 isarranged on the upstream of the diode bridge circuit DB. By arrangingthe power switch 19 directly downstream of the main power source 11,standby power consumption of the entire lighting system is considerablyreduced.

The output from the diode bridge circuit DB is supplied to the commoncathode side of the rectification diodes D3 and D4. To this commoncathode side is connected the first terminal i.e., the positive (+) poleof the smoothing capacitor C1 and a power source voltage supply line 42.The power source voltage supply line 42 is used for supplying a firstpower source voltage DC1 to the chopper circuit 40 and the first lightsource unit 31 provided on the downstream side. The first power sourcevoltage DC1 is about DC 140 V, for example. The diode bridge circuit DBprovides one of the AE/DC converters of the present invention. Moreprecisely, combination of the diode bridge circuit DB and the smoothingcapacitor C1 provides the AC/DC converter.

The daylight white color light source driver 21 further includes a lightsource lighting power source circuit (chopper circuit) 40, in additionto the diode bridge circuit DB. The chopper circuit 40 is avoltage-drop-type DC/DC converter generally called “chopper circuit” andconverts the first power source voltage DC1 to a lower DC voltage.

The chopper circuit 40 includes a switching transistor TR1, a currentdetection resistor R1, a coil L1, a capacitor C2, and a diode D5. Asnoted above, the chopper circuit 40 reduces the first power sourcevoltage DC1 to a voltage DCLED for application to the LEDs, which is avoltage suitable for driving the first light source unit 31.

The capacitor C2 and the coil L1 are connected in series to each other,and this series connection is connected in parallel the diode D5. Thatis, the anode of the diode D5 is connected to the common connection nodeof the capacitor C2 and the coil L1, whereas the cathode of the diode D5is connected to the power source voltage supply line 42.

The common connection node of the coil L1 and the diode D5 is connectedto the drain D of the switching transistor TR1.

When the switching signal Spwm applied to the gate G of the switchingtransistor TR1 is at a high level, the switching transistor TR1 isbrought into a conduction state. At this time, current flows through thefirst light source unit 31, the coil L1, the switching transistor TR1,and the current detection resistor R1 through the power source voltagesupply line 42. Since the voltage generated at the switching transistorTR1 and the current detection resistor R1 is small, the voltage obtainedby subtracting the voltage DCLED from the first power source voltageDC1, i.e., the voltage DC1-DCLED is applied across the coil L1. Forinstance, when the first power source voltage DC1 applied across thesmoothing capacitor C1 is 140V and the voltage DCLED applied to thefirst light source unit 31 is 40V, the voltage (140-40=)100 V is appliedto the coil L1.

When the switching transistor TR1 is in a non-conduction state, i.e.,the switching signal Spwm is at a low level, counter electromotive forceis generated at the coil L1. Due to the counter electromotive force,current flows from the coil L1 to the first light source unit 31 via thediode D5. In this way, regardless of the conduction or non-conduction ofthe switching transistor TR, current is kept supplied to the first lightsource unit 31, so that the first light source unit 31 is kept lit.

The magnitude of the voltage applied to the first light source unit 31depends on e.g. the number of LEDs constituting the first light sourceunit 31. For instance, when a forward voltage for one LED is 3 V and 10LEDs are connected in series, the voltage DCLED for application to theLEDs is 3 V×10=30 V. Similarly, when 20 LEDs are connected in series,the DCLED for application to the LEDs is 3 V×20=60 V. The connection ofLEDs in the LED light source unit is not limited to series connection,and parallel connection may also be employed in combination to drive theLEDs. For instance, when 20 LEDs are used, two strings of LEDs, eachstring made up of 10 LEDs connected in series, may be connected inparallel to each other (10 LEDs×2 rows), or four strings of LEDs, eachstring made up of five LEDs connected in series, may be connected inparallel to each other (5 LEDs×4 rows). The manner of connection can beselected appropriately in accordance with the specification of thelighting system.

The duty ratio of the switching signal Spwm to be applied to the gate Gof the switching transistor TR1 is determined by the magnitude of thefirst power source voltage DC1 and the magnitude of the voltage DCLEDfor application to the LEDs. For instance, when the first power sourcevoltage DC1 is 140 V and the voltage DCLED for application to the LEDsis 40 V, the duty ratio of the switching signal Spwm is 40/140=0.286,i.e., 28.6%. Further, when the first power source voltage DC1 is 140 Vand the voltage DCLED for application to the LEDs is 60 V, the dutyratio of the switching signal Spwm is 60/140=0.429, i.e., 42.9%.

In FIG. 3, the power-saving switch signal S18 for bringing the powerswitch 19 into a conduction state or a non-conduction state is suppliedfrom the signal processing circuit 16.

To control the on/off of the switching transistor TR1, the signalprocessing circuit 16 includes a flip-flop 1610, a comparator 1620 andan oscillator 1630. The flip-flop 1610 includes a set terminal S, areset terminal R and an output terminal Q. When a set signal is inputtedinto the set terminal S, an ON signal is outputted from the outputterminal Q. When a reset signal is inputted into the reset terminal R,the output from the output terminal Q is stopped.

The comparator 1620 compares the voltage Vs detected at the currentdetection resistor R1 with a reference voltage Vref, and supplies areset signal to the reset terminal R of the flip-flop 1610 when thevoltage Vs has reached the reference voltage Vref.

The oscillator 1630 outputs a set signal to the set terminal S of theflip-flop 1610 with a predetermined cycle. When the oscillationfrequency needs to be changed in accordance with the magnitude of thefirst power source voltage DC1, a voltage-controlled oscillator (VCO)may be used.

FIG. 4 shows the specific circuit structure of the switch drivingcircuit 18 of the present invention shown in FIGS. 1 and 2. Forinstance, the switch driving circuit 18 is made up of transistors TR2,TR3 and resistors R2, R3, R4, R5, R6. Although the transistors TR2, TR3are bipolar transistors in this example, these may be MOS transistors.

The resistor R3 is connected between the base and the emitter of thetransistor TR2. The resistor R3 determines the magnitude of the currentflowing to the base side of the transistor TR2. The emitter of thetransistor TR2 is connected to the ground potential GND.

The collector of the transistor TR2 is connected to the first terminalof the resistor R4, and the second terminal of the resistor R4 isconnected to the base of the transistor TR3 and the first terminal ofthe resistor R5. The second terminal of the resistor R5 is connected tothe emitter of the transistor TR3 and the first terminal of the resistorR6. The second terminal of the resistor R6 is connected to the powersource voltage VDD. The power source voltage VDD is set to e.g. 5 V.

The resistors R6, R5, R4 determine the current to flow through thetransistor TR2.

An instruction signal S16 is applied from the signal processing circuit16 to the base of the transistor TR2 via the resistor R2. The transistorTR2 is conducted when the instruction signal S16 is at a high level andheld in a non-conduction state when the instruction signal S16 is at alow level. That is, the transistor TR2 responds to the level of theinstruction signal S16.

The switching between the conduction state and the non-conduction stateof the transistor TR2 and the transistor TR3 are in synchronism witheach other. That is, when the transistor TR2 is in a conduction state,the transistor TR3 is also in a conduction state. Similarly, whentransistor TR2 is in a non-conduction state, the transistor TR3 is alsoin a non-conduction state.

When the instruction signal outputted from the signal processing circuit16 is at a low level, current does not flow through the coil L2. In thisstate, the first terminal 191 and the second terminal 192 of the powerswitch 19 are held open. This type of switching is herein called anormally open system. Conversely, the switching system in which thefirst terminal 191 and the second terminal 192 are held short-circuitedi.e., electrically connected to each other when the current is notflowing through the coil 12 is herein called a normally closed system.

In the normally open system, when the instruction signal S16 changes toa high level, current flows through the coil L12, and the first terminal191 and the second terminal 192 shift from the open state to theshort-circuited state. On the other hand, in the normally closed system,the first terminal 191 and the second terminal 192 shift from theshort-circuited state to the open state.

The power switch 19 used in the lighting system of the present inventionmay be either of the normally open system or of the normally closedsystem.

It is also possible to arrange such that current does not flow throughthe coil L2 when the instruction signal S16 is at a high level and flowswhen the instruction signal S16 is at a low level. In this way,selection between the supply and shut off of the current to the coil L2in accordance with the high level and the level of the instructionsignal S16 can be arranged appropriately, by changing the circuitstructure of the switch driving circuit 18, which can be easilyperformed.

In any case, to reduce the standby power in the lighting system 100,200, power supply to the daylight white color light source driver 21,the incandescent color light source driver 22, the daylight color lightsource driver 23, the white color light source driver 24, and the warmwhite color light source driver 25 need to be shut off, i.e., the firstterminal 191 and the second terminal 192 of the power switch 19 need tobe set to be disconnected or open.

FIG. 5 shows a lighting system of the present invention in which aPhoto-MOS relay is used as the power switch 19. A Photo-MOS relay is oneof known solid state relays.

The power switch 19 includes transistors TR4, TR5 and diodes D6, D7.Each of the transistors TR4, TR5 may comprise e.g. an N-channel MOStransistor. Of course, an NPN bipolar transistor may be used instead.The respective sources S of the transistors TR4 and TR5 are commonlyconnected.

The drain D of the transistor TR4 and the cathode of the diode D6 arecommonly connected, and the common connection node is connected to thefirst terminal 191 of the power switch 19. To the first terminal 191, ACvoltage AC1 from the main power source 11 is applied.

The respective anodes of the diode D6 and the diode D7 are commonlyconnected, and the common connection node is connected to the sources Sof the transistor TR4, TR5.

The drain D of the transistor TR5 and the cathode of the diode D7 arecommonly connected, and the common connection node is connected tosecond terminal 192 of the power switch 19.

The respective gates G of transistors TR4 and TR5 are commonlyconnected. The commonly connected gates G are connected to the controlterminal 193. Actually, a photo-electric conversion cell, not shown, isdisposed on the common gate G side. When the light emitting diode LED 5is lit, the photo-electric conversion cell increases the voltage betweenthe gate G and the source S to cause conduction.

A voltage, not shown, generated due to the light from the light emittingdiode LED5 is applied to the control terminal 193. Signals received bythe remote controller receiver 17 shown in FIGS. 1 and 2 can be appliedto the LED 5. Further, the power-saving switch signal S18 outputted fromthe switch driving circuit 18 or an optical signal generated based onthe instruction signal S16 outputted from the signal processing circuit16 can also be applied to the LED 5.

There are two types of Photo-MOS relays, i.e., “make” type and “break”type. The “make” type corresponds to the normally open system describedabove. That is, with the “make” type, the transistors TR4 and TR5 areheld in a non-conduction state when the LED 5 is not lit, and thevoltage between the gate G and the source S of the transistor TR4, TR5is increased to cause conduction when the LED 5 is lit.

The “break” type corresponds to the normally closed system describedabove. With the “break” type, the transistors TR4 and TR5 are held in aconduction state when the LED 5 is not lit, while the transistors TR4and TR5 are brought into a non-conduction state when the LED is lit, byreversing the direction between the gate G and the source S of thetransistors TR4, TR5.

The power switch 19 of the present invention can employ either the“make” type Photo-MOS relay or the “break” type Photo-MOS relay.

In the Photo-MOS relay shown in FIG. 5, the transistors TR4, TR5 operatein response to the voltage applied to control terminal 193 of the powerswitch 19, whereby the conduction and non-conduction between the firstterminal 191 and the second terminal 192 is controlled. In this way, forthe power switch 19 of the lighting system 100, 200 of the presentinvention, not only a mechanical relay but also a solid state relay maybe employed.

FIG. 6 schematically illustrates a power switch 19 in which a phototriac relay is used. The photo triac relay is a type of solid staterelay. A triac is a semiconductor element in which two thyristors arearranged in antiparallel connection for allowing current to flow in bothdirections. The photo triac relay in the present invention comprises acombination of a so-called triac and a photo triac.

The power switch 19 includes a triac TRIAC. The triac TRIAC has a firstterminal T1 connected to the first terminal 191 of the power switch 19,and a second terminal T2 connected to the second terminal 192. Aso-called trigger electrode for controlling the triac TRIAC is connectedto the control terminal 193.

The photo triac relay is illustrated as simplified in FIG. 6. Actually,however, on the control terminal 193 side is arranged a photo triac or aphoto coupler optically coupled to the infrared light emitting diode LED6. Further, a zero-cross circuit or a trigger circuit for triggering thetriac TRIAC is often connected to the control terminal 193 side.Further, it is well known to arrange a surge absorption circuit betweenthe first terminal T1 and the second terminal T2 of the triac. TRIAC.

FIG. 7 schematically shows an example of the power-saving switch signalS18 that is outputted from the switch driving circuit 18 and brings thedaylight white color light source driver 21, the incandescent colorlight source driver 22, the daylight color light source driver 23, thewhite color light source driver 24, and the warm white color lightsource driver 25 into a conduction state or a non-conduction state.

The power-saving switch signal S18 becomes a high level HI at the timet1 at the same time as the AC voltage AC1 is applied. At this time, thefirst through the fifth light source units 31-35 are turned on. At timet2, the power-saving switch signal S18 is shifted from the high level HIto the low level LO to turn off these light source units. The light offperiod continues to the time t3, when the light source units are turnedon again.

In the example shown in FIG. 7, each light source unit is turned on whenthe power-saving switch signal S18 is at a high level HI and turned offwhen the power-saving switch signal S18 is at a low level LO. However,as noted before, a reverse arrangement is also possible. That is, thesystem can be easily arranged such that each light source unit is turnedon when the power-saving switch signal S18 is at a low level to andturned off when the power-saving switch signal S18 is at a high levelHI.

Third Embodiment

FIG. 8 shows a third embodiment of a lighting system according to thepresent invention. The third embodiment is similar to the embodimentsshown in FIGS. 1 and 2 in that the third embodiment also includes themain power source 11, the control circuit 12, the switch driving circuit18, and the power switch 19. Unlike the first and the second embodiment,the third embodiment includes a first LED lighting unit 310, a secondLED lighting unit 320, and a third LED lighting unit 330.

The first LED lighting unit 310 includes a first constant-currentcircuit 311 and a first LED circuit 312. The first constant-currentcircuit 311 supplies a constant current CC1 to the first LED circuit312. The second LED lighting unit 320 includes a second constant-currentcircuit 321 and a second LED circuit 322. The second constant-currentcircuit 321 supplies a constant current CC1 to the second LED circuit322. The third LED lighting unit 330 includes a third constant-currentcircuit 331 and a third LED circuit 332. The third constant-currentcircuit 331 supplies a constant current CC1 to the third LED circuit332. These three lighting units can be set to a single colortemperature. For instance, all the three LED lighting units may be forthe daylight white color light source. Alternatively, all the three LEDlighting units may be for the incandescent color light source.Alternatively, these LED lighting units may be designed for a colortemperature corresponding to one of the daylight color, the white colorand the warm white color defined in JIS Standard Z-9912. Alternatively,similarly to the first and the second embodiments shown in FIGS. 1 and2, these LED lighting units may provide a plurality of light sources ofdifferent color temperatures.

Although three LED lighting units, i.e., the first through the third LEDlighting unit 310-330 are shown in FIG. 8, more than three LED lightingunits or less than three LED lighting units may be provided.

As a large difference of the third embodiment shown in FIG. 8 from thefirst and the second embodiments shown in FIGS. 1 and 2, an AC/DCconverter 130 and a DC/DC converter 150 are provided directly downstreamof the power switch 19. The AC/DC converter 130 converts the AC voltageAC1 into a DC voltage DC10, and the DC/DC converter 150 converts the DCvoltage DC10 into a DC voltage DC20. The DC voltage DC20 is supplied tothe first LED circuit 312 via the first constant-current circuit 311.The DC voltage DC20 is also supplied to the second LED circuit 322 viathe second constant-current circuit 321. The DC voltage DC20 is alsosupplied to the third LED circuit 332 via the third constant-currentcircuit 331.

Although the AC/DC converter 130 and the DC/DC converter 150 in thelighting system 800 shown in FIG. 8 are used commonly for the threelighting units, i.e., the first LED lighting unit 310, the second LEDlighting unit 320 and the third LED lighting unit 330, an AC/DCconverter 130 and a DC/DC converter 150 may be provided individually foreach of the LED lighting units.

Fourth Embodiment

FIG. 9 shows a lighting system 900 according to a fourth embodiment ofthe present invention. The fourth embodiment is obtained by changingpart of the third embodiment shown in FIG. 8. Specifically, in theembodiment shown in FIG. 8, the control circuit 12 is provided togenerate a power source voltage for driving the signal processingcircuit 16, and the AC/DC converter 13, the transformer 14 and the DC/DCconverter 15 are provided in the control circuit 12. Unlike this, theembodiment shown in FIG. 9 does not use these circuit portions but usesa DC voltage source VBAT instead. The DC voltage source VBAT maycomprise a battery of 3.3 V or 5.0 V. According to the fourthembodiment, the size and cost of the entire lighting system can bereduced as compared with the first, the second and the thirdembodiments.

Fifth Embodiment

FIG. 10 shows a lighting system 1000 according to a fifth embodiment ofthe present invention. In the fourth embodiment shown in FIG. 9, an ACvoltage AC1 is supplied from the main power source 11 to the powerswitch 19. Unlike this, in the embodiment of FIG. 10, a main powersource 11 a of DC voltage is provided. That is, although the main powersource 11 supplies an AC voltage AC1 in all the first through the fourthembodiments, the main power source 11 a of the fifth embodiment shown inFIG. 10 supplies a DC voltage. At present, a ceiling light directlyfixed to the ceiling of a room is usually operated with an AC voltagefrom a commercial power source. However, it is expected that in thefuture a larger number of LED lamps, organic EL devices, fluorescentlamps or high intensity discharge (HID) lamps are operated with a DCpower source provided by a private electricity generation system. Thelighting system of the present invention is also applicable to such asituation.

FIG. 11 shows a specific circuit structure of the first LED lightingunit 310 shown in FIGS. 8, 9 and 10. It is to be noted that the specificcircuit structures of the second LED lighting unit 320 and the third LEDlighting unit 330 are basically the same as that shown in FIG. 11.

To the first LED lighting unit 310 shown in FIG. 11, DC voltage V40 issupplied through the DC voltage supply line 340. The constant currentCC1 generated at the first constant-current circuit 311 flows throughthe DC voltage supply line 34 to the light emitting diodes LED1, LED2,LED3, and LED4 in the mentioned order. To this series connection of thelight emitting diodes LED1, LED2, LED3, LED4 is connected the collectorof a transistor TR6. To the base of the transistor TR6 is applied apulse signal. The pulse width of the pulse signal is controlled so thatthe brightness of the light emitting diodes LED1-LED4 is adjusted.Namely, the brightness of the light from the light emitting diodesLED1-LED4 is controlled based on the pulse width of the PWM signal Spwm.In this way, the circuit structure shown in FIG. 11 employs a method ofadjusting brightness by duty control, using a constant current. Asalready described with reference to FIG. 3, the LED light sources of thepresent invention do not necessarily need to be connected in series, andparallel connection may also be used in combination.

As illustrated by the broken line in FIG. 11, the constant current CC1may be replaced with a resistor R7. Such a structure is known as abrightness adjustment method by duty control using a constant voltage.This circuit structure has an advantage that the structure is simple ascompared with the circuit for the constant-current method, though theremay be a disadvantage that the brightness of the light changes when theforward voltages of the light emitting diodes LED1-LED4 are biased.

As described above, the lighting system according to the presentinvention ensures considerable standby power reduction. The presentinvention is particularly applicable to a lighting system which needs toprovide a high brightness or a large-size lighting system having highpower consumption.

1B Embodiment

Described below with reference to the drawings is a 1B embodimentaccording to a variation of the present invention. In the drawingsreferred to below, the elements that are identical or similar aredesignated by the same or similar reference signs. The drawings are onlyschematic and the dimensional relationship or ratio betweencorresponding parts may differ between the drawings.

Shown in FIG. 13 is a chromaticity/brightness control map for describinga method of adjusting the brightness and/or chromaticity of lightemitted from an LED lighting apparatus according to the variation of thepresent invention. As shown in FIG. 16, the LED lighting apparatusaccording to the variation of the present invention includes two typesof white LEDs (light emitting diodes) which emit light of differentcolor temperatures (hues).

As defined also in JIS standard, the white color range includes, from ahigher color temperature, a daylight color (color temperature: about5700-7100 K), a daylight white color (color temperature: about 4600-5400K), a white color (color temperature: about 3900-4500 K), a warm whitecolor (color temperature: about 3200-3700 K), and an incandescent color(color temperature: about 2600-3150 K), and LEDs of any of these huesmay be employed. In other words, the light emitting portion according tothe variation of the present invention may comprise two groups of LEDsselected from a daylight color LED group, daylight white color LEDgroup, a white color LED group, a warm white color LED group and anincandescent color LED group.

Preferably, the light emitting portion comprises LEDs of the daylightwhite color LED group and the incandescent color LED group.

Specifically, as shown in FIG. 16, a plurality of LEDs of theincandescent color (hereinafter referred to as “L color”) and aplurality of LEDs of the daylight white color (hereinafter referred toas “N color”) are alternately arranged in a circle. That is, LEDs of theL color and LEDs of the N color are used in combination as arranged toform a circle generally concentric with the power source cover providedat the center. With this arrangement, when the brightness of theincandescent color LEDs or the brightness of the daylight white colorLEDs is changed, both the chromaticity and brightness change. When thelight output from the both types of LEDs is increased without changingthe ratio between the brightness of the incandescent color LEDs and thatof the daylight white color LEDs, the brightness increases, with thechromaticity remains unchanged. When the light output from both types ofLEDs is reduced, the brightness decreases, with the chromaticity remainsunchanged.

Herein, each LED element comprises e.g. an n-type semiconductor layermade of a GaN-based semiconductor, a p-type semiconductor layer, and anactive layer sandwiched between these semiconductor layers. The LEDelement emits e.g. blue light.

The LED element is covered with a sealing resin. The sealing resin ismade of e.g. a transparent epoxy resin or a silicone resin mixed with afluorescent substance. The fluorescent substance emits yellow light whenexcited by blue light emitted from the LED element. The yellow light ismixed with blue light emitted from the LED element, whereby white lightis obtained. The sealing resin may contain a fluorescent substance thatemits red light when excited by blue light and a fluorescent substancethat emits green light when excited by blue light.

The chromaticity/brightness control map shown in FIG. 13 indicates howthe chromaticity changes with changes in brightness of the incandescentcolor (L color) LEDs and changes in brightness of the daylight whitecolor (N color) LEDs. At the point A in the chromaticity/brightnesscontrol map, both the output from the T-color LEDs and the output fromthe N-color LEDS are at the maximum. That is, at the point A, thebrightness obtained by the two types of LEDs is at the maximum, and thecolor temperature ratio between the L color and the N color is 1:1. Atthe point B, the output from the L-color LEDs is at the maximum, whereasthe output from the N-color LEDs is 0 (“light OFF” state). That is, thebrightness at the point B is half the brightness at the point A, and thecolor temperature (chromaticity) at the point B is the lowest (2900 K).

At the point C, the output from the L-color LEDs is 0 (“light OFF”state) and the output from the N-color LEDs is at the maximum. That is,the brightness at the point C is equal to the brightness at the point Band half the brightness at the point A. The color temperature(chromaticity) at the point C is the highest (5000 K). At the point D,both the output from the L-color LEDS and the output from the N-colorLEDs are 0 (“light OFF” state). That is, the brightness by the two typesof LEDs at the point D is at the minimum (“light OFF” state). The colortemperature (chromaticity) at the point D is equal to that at the pointA, i.e., just in the middle of the point B and the point C.

By changing the respective outputs from the L-color LEDs and the N-colorLEDs between 0 (“light OFF” state) and the maximum, the range surroundedby the square shown in the figure, which is defined by the solid linesconnecting the four points A, B, C and D, is considered to be covered.However, both the L-color LEDs and the N-color LEDs have variations inoutput. Thus, the brightness and chromaticity in the square surroundedby the four points A, B, C and D may not be fully covered. That is, insome lighting systems, the coverable range of the chromaticity andbrightness does not correspond to the square of the four points A, B, Cand D shown in FIG. 13.

Thus, taking variations in output of the LEDs into consideration,instead of setting the range defined by the four points A, B, C, and Dcovering the maximum light output as the rated output range forchromaticity and brightness, the range surrounded by the broken lines inthe figure which connect four points A′, B′, C′ and D′ positioned inwardof the points A, B, C, D is set as the rated output range.

Generally, an LED is connected to a constant-current source and drivenby a PWM (pulse width modulation) signal by electric current. Thus, inorder to change the output from an LED, the duty ratio of the ON periodof a PWM signal outputted from the LED driver is changed. To maximizethe light output from an LED, the LED is driven with the duty ratio of100%. To minimize the light output from an LED (turn off the LED), theLED is driven with the duty ratio of 0%. However, light output from theL-color LEDs and light output from the N-color LEDs are made neithermaximum nor minimum at the points A′, B′, C′ and D′.

FIGS. 15A and 15B show a relationship between a PWM signal and theoutput from L-color LEDs or the output from the N-color LEDs. FIG. 21shows examples of a PWM signal for the N-color LEDs and a PWM signal forthe L-color LEDs. The pulse P1 in FIG. 21 is a PWM signal for theN-color LEDs, whereas the pulse P2 in FIG. 21 is a PWM signal for theL-color LEDs.

The pulse P1 is a pulse signal having a cycle t. The ON period isindicated by t1. The duty ratio of the pulse P1 is 100×(t1/t) %. Thepulse 22 is a pulse signal having a cycle t. The ON period is indicatedby t2. The duty ratio of the pulse P2 is 100×(t2/t) %. The light outputfrom the N-color LEDs is changed by changing the ON period t1 in thepulse P1 to the period indicated by the broken lines (pulse widthmodulation). The light output from the L-color LEDs is changed bychanging the ON period t2 in the pulse P1 to the period indicated by thebroken lines (pulse width modulation).

For instance, when the duty ratio of the pulse P1 is 100%, the lightoutput from the N-color LEDs is at the maximum. When the duty ratio ofthe pulse P1 is 0%, the light output from the N-color LEDs is at theminimum. These hold true for the pulse P2. For instance, when the ONperiod t2 of the pulse P2 is linearly increased, the duty ratio linearlyincreases, so that the brightness increases linearly (stepwise). Whenthe ON period t2 is linearly decreased, the duty ratio linearlydecreases, so that the brightness decreases linearly (stepwise). Thesehold true for the pulse P1.

For instance, when the ON period t1 of the pulse P1 is non-linearlyincreased, the duty ratio increases non-linearly, so that the brightnessincreases non-linearly. When the ON period t1 is non-linearly decreased,the duty ratio decreases non-linearly, so that the brightness decreasesnon-linearly. Examples of non-linear increase/decrease includeexponential increase/decrease and increase/decrease based on quadraticfunction. These hold true for the pulse P2.

In FIGS. 15A and 15B, L indicates the L-color, whereas N indicates theN-color. FIG. 15A shows the duty ratios of a PWM signal for the LEDs atthe four points A, B, C and D. At the point A, the duty ratio is 100%(maximum output) for both the L-color and the N-color. At the point B,the duty ratio for the L-color is 100%, whereas the duty ratio for theN-color is 0% (minimum output). At the point C, the duty ratio for theL-color is 0%, whereas the duty ratio for the N-color is 100%. At thepoint D, the duty ratio is 0% for both the L color and the N color.

FIG. 15B shows the duty ratios of a PWM signal for the LEDs at the fourpoints A′, B′, C′ and D′. At each of the four points, the light outputfrom the L-color LEDs and the light output from the N-color LEDs have amargin (allowance) of α %. Herein, α>0. At the point A′, the duty ratiois (100−α) % for both the L-color and the N-color. At the point B′, theduty ratio for the N-color is (100−α) %, whereas the duty ratio for theN-color is α %. At the point C′, the duty ratio for the L-color is α %,whereas the duty ratio for the N-color is (100−α) %. At the point D′,the duty ratio is α % for both the L color and the N color.

That is, at the point A′, the brightness is decreased by 2α % while thechromaticity is maintained, as compared with the point A. At the pointB′, the brightness is maintained while the chromaticity is increased by2α %, as compared with the point B. At the point C′, the brightness ismaintained while the chromaticity is decreased by 2α %, as compared withthe point C. At the point D′, the brightness is increased by 2α % whilethe chromaticity is maintained, as compared with the point D.

By securing margins in this way, the rated output range for brightnessand chromaticity can be adjusted as required, as shown in FIGS. 14A-14D,for example. As will be understood by referring to the position of FIG.13, FIG. 14A indicates that the region surrounded by the four points A′,B′, C′, D′ can be translated upward by up to 2α %. In the state shown inFIG. 14A, the point A′ corresponds to the point A. FIG. 14B indicatesthat the region surrounded by the four points A′, B′, C′, D′ can betranslated leftward by up to 2α %. In the state shown in FIG. 14B, thepoint B′ corresponds to the point B. FIG. 14C indicates that the regionsurrounded by the four points A′, B′, C′, D′ can be translated rightwardby up to 2α %. In the state shown in FIG. 14C, the point C′ correspondsto the point C. FIG. 14D indicates that the region surrounded by thefour points A′, B′, C′, D′ can be translated downward by up to 2α %. Inthe state shown in FIG. 14D, the point D′ corresponds to the point D.

That is, when a LED lighting apparatus is completed, brightness andchromaticity of the lighting apparatus are measured to make achromaticity/brightness control map. The four points of thechromaticity/brightness control map should be at the positions of thepoints of A′, B′, C′ and D′, respectively. However, when the brightnessis entirely low and the chromaticity/brightness control map is closer tothe point D, the upward shift as shown in FIG. 14A is performed, i.e.,adjustment is performed to make the four points of the map correspond tothe points A′, B′, C′ and D′. In this way, by performing adjustmentwithin the margin of a, LED lighting apparatuses having a uniform ratedoutput are obtained.

Preferably, the margin α is set to correspond to the variation range ofthe light output from the L-color LEDs and the light output from theN-color LEDs. A test performed with respect to some samples revealed thefollowing: in the samples of L-color LEDs which had the largestvariation in light output, when compared at the maximum output (dutyratio: 100%), the duty ratio of the LED having the highest brightnessneeds to be made 70% in order to make the brightness of that LEDcorrespond to the brightness of the LED having the lowest brightness. Onthe other hand, in the samples which had the smallest variation in lightoutput, when compared at the maximum output, the duty ratio of the LEDhaving the highest brightness needs to be made 89% in order to make thebrightness of that LED correspond to the brightness of the LED havingthe lowest brightness. It is to be noted that the minimum output of anLED indicates that the LED is completely put out. Thus, no variationexists, and the minimum value of the duty ratio is 0%. The resultssimilar to the above were obtained with respect to the N-color LEDsamples. From these results, when largest variations in the light outputfrom the L-color LEDs and the light output from the N-color LEDs aretaken into consideration, it is preferable that 0<α<30(%).

In this way, by providing both the L-color LEDs and the N-color LEDswith a predetermined light output margin α and adjusting the lightoutputs based on the results of a test before shipment from the factory,all the LED lighting apparatuses can be adjusted to emit light in auniform brightness/chromaticity range. Moreover, when a user cannot besatisfied with the brightness/chromaticity range set before theshipment, the LED lighting apparatus can be configured such that theuser can set the range of a as desired.

Specifically, the average value of variations in chromaticity of theN-color LEDs is represented as C_(N). The absolute value of the maximumvariation in chromaticity of the N-color LEDs is represented as C_(NM).The average value of variations in chromaticity of the L-color LEDs isrepresented as C_(L). The absolute value of the maximum variation inchromaticity of the L-color LEDs is represented as C_(LM). The averagevalue of variations in brightness of the N-color LEDs is represented asI_(N). The absolute value of the maximum variation in brightness of theN-color LEDs is represented as I_(NM). The average value of variationsin brightness of the L-color LEDs is represented as I_(L). The absolutevalue of the maximum variation in brightness of the L-color LEDs isrepresented as I_(LM). The average value of variations in chromaticityof all the LEDs including the N-color and the L-color is represented asCB. The absolute value of the maximum variation in chromaticity of allthe LEDs including the N-color and the L-color is represented as CB_(M).The average value of variations in brightness of all the LEDs includingthe N-color and the L-color is represented as 1B. The absolute value ofthe maximum variation in brightness of all the LEDs including theN-color the L-color is represented as IB_(M). Further, C1=MAX(C_(N),C_(L)), I1=MAX (I_(N),I_(L)), C2=MAX (C_(NM), C_(LM)), I2=MAX(T_(NM), I_(LM)), −C2≦C1≦C2, −I2≦I1≦I2. Herein, actually, C2 is about4(%), and I2 is about 8(%).

The number of color tones as a whole is represented as a, the number ofbrightness levels as a whole is represented as b, the color tone and thebrightness level when the N-color LEDs and the L-color LEDs are on arerepresented by x and y, respectively. Herein, for instance, a can be setto about 73, and b can be set to about 73. As shown in FIG. 21, the PWMsignal for the N-color LEDs is represented as P1, the PWM signal for theL-color LEDs is represented as P2, the duty ratio of P1 is representedas PN, and the duty ratio of P2 is represented as PL. Herein, 0≦PN≦1,and 0≦PL≦1. When the mutual light emitting efficiency correction factorof the N-color LEDs and the L-color LEDs is represented by ω,PN=(1−C2−C1)×ω×(x/a)×(1−I2−I1)×(y/b) andPL=(1−C2−C1)×ω×((a−x+1)/a)×(1−I2−I1)×(y/b). Herein, ω can be set toabout 0.9.

(1−C2−C1)×(1−I2−I1) of PN or PL is equal to(1−(I2+I1)−(C2+C1)+(C2+C1)(I2+I1)), among which−(C2+C1+I2+I1)+(C2+C1)(I2+I1) corresponds to the correction range oradjustment range α.

Conventionally, operations to light or put out an LED lighting apparatussuch as a ceiling light is performed as shown in FIG. 17. First, whenthe power switch is turned on by the operation of e.g. a remotecontroller, brightness increases linearly (stepwise) for a brightnessincreasing operation period of T11, which may be 4.5 seconds, from thestart of lighting to the completion of lighting. After 4.5 seconds, thebrightness reaches the point A′ shown in FIG. 13. On the other hand,when the power switch is turned off (at the point “OFF” indicated in thefigure), the brightness decreases linearly for a brightness decreasingoperation period of T12 which is equal to the brightness increasingoperation period of T11, from the start of putting-out to the completionof putting-out, and the light is finally put out. Such linear increaseand decrease of brightness is employed to prevent dazzling and providesa sense of high quality.

In the case of FIG. 17, when lighting is performed by linearlyincreasing the brightness from the non-lighting state to the completionof lighting, humans can easily notice the lighting operation sensuously.However, when putting-out of a light is performed by linearly decreasingbrightness from the lighting state to the completion of put-outoperation, it is sometimes difficult for humans to sensuously noticethat the put-out operation is properly working. Thus, although theput-out operation is proceeding, the user may sometimes press the powerswitch again, making the process return to the lighting operation.

To solve such a problem, the brightness decreasing operation period ismade shorter than the brightness increasing operation period. FIG. 18shows an example of brightness increasing operation period andbrightness decreasing operation period. When the power source switch isturned on, the brightness increasing operation is performed for thebrightness increasing operation period of T11 equal to that shown inFIG. 17, i.e., for 4.5 seconds, and lighting is completed after thelapse of the period T11. On the other hand, when the power switch isturned off, brightness is decreased linearly (stepwise) for two seconds,as indicated as the brightness decreasing period T21 shown in FIG. 18,and putting-out is completed finally. The brightness decreasing periodT21 is two seconds, which is shorter than the brightness increasingperiod T11. The brightness decreasing operation performed linearly(stepwise) in a shorter period of time in this way is easy for humans tonotice sensuously. Preferably, the brightness decreasing period T21 ishalf or less than the brightness increasing period T11. That is,T21≦(½)×T11.

Alternatively, the put-out operation may be performed as shown in FIG.19. In the example shown in FIG. 19, the brightness increasing period isequal to that shown in FIGS. 17 and 18, whereas the brightnessdecreasing period T31 is 2.5 seconds. In the example shown in FIG. 19,the linear (stepwise) brightness decreasing operation like that shown inFIG. 18 is not performed. Instead, as indicated in the portion T1 in thefigure, brightness is rapidly decreased in the first half periodimmediately after the power source switch is turned off. Then, in thelatter half period, brightness is decreased slowly as indicated in theportion T2. In this way, a non-linear brightness decreasing operationperiod. T31, in which brightness is decreased exponentially can also beemployed. In this case, since the brightness decreases rapidly in thefirst half period, the user can easily notice sensuously. Further, sincethe brightness decreasing speed drops in the latter half period, theentire brightness decreasing period is sufficiently long, so that asense of high quality can be provided.

The brightness decreasing operation to put out the light in FIGS. 18 and19 is based on the assumption that both the brightness of the L-colorLEDs and the brightness of the N-color LEDs are decreased, i.e., theduty ratios of the both PWM signals are reduced to put out the light.However, in the brightness decreasing operation of FIGS. 18 and 19, onlythe brightness of the N-color LEDs may be decreased, instead ofdecreasing brightness of both of the L-color LEDs and the N-color LEDs.It is known that humans can notice change in brightness more easily whenthe brightness of the N-color, which is closer to pale white, or has ahigher color temperature, is decreased. Thus, this arrangement issuitable for preventing erroneous operation due to erroneousrecognition.

FIG. 20 shows the specific structure of the LED lighting apparatusaccording to the variation of the present invention. The LED lightingapparatus 100B is connected to an AC power source 1 by attaching itsbase 3 to a socket 2. The LED lighting apparatus 100B includes an AC/DCconverter 4, a delay unit 5, a first LED driver 6 for supplying adriving signal to the daylight white color LEDs 7, daylight white colorLEDs 7, a second LED driver 8 for supplying a driving signal to theincandescent color LEDs 9, incandescent color LEDs 9, an MPU 10, aphotodiode 11B, and a preamplifier 30. The MPU 10 is a microprocessorunit and controls each part, performs computations, and supplies a PWMsignal to the first LED driver 6 and the second LED driver 8.

The first LED driver 6 and the second LED driver 8 are elements fordriving the LEDs with a constant-current and performing brightnessadjustment by a PWM (pulse width modulation) signal.

The AC voltage inputted is converted into a DC voltage at the AC/DCconverter 4 and supplied to each of the delay unit 5, the first LEDdriver 6, the second LED driver 8, the MPU 10, the photodiode 11B andthe preamplifier 30. In FIG. 20, the solid lines extending from theAC/DC converter 4 basically represent power lines, whereas the brokenlines connecting blocks to each other basically represent signal lines.

The preamplifier 30 is made up of an amplifier 12B, a limiter 13B, aband-pass filter 15B, a detector circuit 16B, and a wave-shaping circuit17B.

The AC power source 1 and the socket 2 are provided outside the LEDlighting apparatus 100B. The infrared remote controller transmitter 20is used to turn on or off the LED lighting apparatus 100B and adjust therange of brightness and chromaticity of the light to be emitted. Theinfrared remote controller transmitter 20 has a light emitting diode foremitting infrared and hence sends out an infrared signal (IR signal).The IR signal is a signal subjected to pulse position modulation (PPM)and amplitude modulation. This signal is received by the photodiode 11Bprovided in the LED lighting apparatus 100B.

First, when the lighting-start (full lighting) switch of the infraredremote controller transmitter 20 is pressed, an TR signal is outputtedfrom the infrared remote controller transmitter 20, which is received bythe photodiode 11B. The IR signal is a serial signal subjected to PPM oramplitude modulation, and the amplitude is modulated with a 38 kHzcarrier wave. The TR signal is converted into a current signal at thephotodiode 11B and then converted and amplified into a voltage signal bythe amplifier 12B. The voltage signals of different amplitudes outputtedfrom the amplifier 12B is amplified by the limiter 13B into voltageoutput signals of a constant amplitude.

Of the signals outputted from the limiter 15B, the band-pass filterpasses only the signals within the frequency range of the carrier waveand removes pulse wave distortion, noises and so on, whereby signals areconverted into a proper digital level.

The signal is then transmitted to the MPU 10. The MPU 10 supplies a PWMsignal P1 and a PWM signal P2 to the first LED driver 6 and the secondLED driver 8, respectively, to perform full lighting of the N-color LEDs7 and the L-color LEDs 9. The PWM signal P1 and the PWM signal P2 aresignals having the same pulse shape as the PWM signals P1 and P2described with reference to FIG. 21. The difference lies in that, sincethe LEDs are driven by a current, the PWM signals P1 and P2, which arevoltage signals of a digital circuit, are converted by the first LEDdriver 6 and the second LED driver 8 into current pulse signals withinthe range of the LED driving current.

In starting the lighting, as shown in FIGS. 18 and 19, the light outputis linearly (stepwise) increased. Specifically, as described withreference to FIG. 21, brightness is increased by stepwise and linearlyincreasing the duty ratios of the PWM signal P1 and the PWM signal P2 bythe control by the MPU 10. When the MPU 10 finally outputs the PWMsignals P1 and P2 having the duty ratio of the point A′ shown in FIGS.13 and 15, the lighting is completed. By this, the LEDs 7 and the LEDs 9are fully lighted.

Next, put-out operation is described. When the put-out switch of theinfrared remote controller transmitter 20 is pressed, an IR signal isoutputted from the infrared remote controller transmitter 20, which isreceived by the photodiode 11B. The subsequent process before thedigital signal is transmitted to the MPU 10 is the same as the processin starting the lighting, so that the description is omitted. Asdescribed with reference to FIGS. 18 and 19, in putting out the light,brightness is decreased linearly or non-linearly. Specifically, asdescribed with reference to FIG. 21, brightness is decreased by linearlyor non-linearly decreasing the duty ratios of the PWM signal P1 and thePWM signal P2 by the control by the MPU 10. When the MPU 10 finallyoutputs the PWM signals P1 and P2 having the duty ratio of the point D′shown in FIGS. 13 and 15, the putting out is completed.

However, as shown in FIG. 14, depending on the correction method, withthe duty ratio of the point D′, the duty ratio cannot be made 0%. Tocompletely put out the light, the DC power source voltage for supply tothe first LED driver 6 and the second LED driver 8 needs to be turnedoff. Thus, the MPU 10 outputs an OFF signal to the delay unit 5. Thedelay unit 5 shuts off the power line after a delay of a predeterminedtime from the reception of the OFF signal from the MPU 10, and turns offthe DC power source voltage supplied to the first LED driver 6 and thesecond LED driver 8.

The delay unit 5 has several delay lines. In the case of the put-outoperation shown in FIG. 18, a delay line is selected which turns off theDC power source voltage after a delay of the period T21 from thereception of the OFF signal from the MPU 10. On the other hand, in thecase of the put-out operation shown in FIG. 19, a delay line is selectedwhich turns off the DC power source voltage after a delay of the periodT31 from the reception of the OFF signal from the MPU 10. In this way,the put-out operation is completed.

In order for the user to be able to change the value of a shown in FIG.15, the apparatus is configured such that the rated output range can bechanged in accordance with a signal from the infrared remote controllertransmitter 20 by changing the upper and the lower limits of the dutyratios of the PWM signals P1, P2 at the MPU 10.

The feature of the present variation of the invention is described belowas Appendixes.

Appendix 1

An LED lighting apparatus comprising:

-   -   a light emitting portion including a first LED and a second LED        having different color temperatures and arranged alternately;        and    -   a light output controller for generating a first PWM signal for        driving the first LED and a second PWM signal for driving the        second LED;    -   wherein a rated output range of each of a duty ratio of the        first PWM signal and a duty ratio of the second PWM signal is        set to a range of from (0+α) to (100−α) %, where α represents an        output range for correction and satisfies 0<α<30.

Appendix 2

The LED lighting apparatus as set forth in Appendix 1, wherein each ofthe duty ratio of the first PWM signal and the duty ratio of the secondPWM signal is linearly adjusted by the light output controller so thatbrightness increasing operation from start of lighting to completion oflighting is performed linearly, and time for brightness decreasingoperation from start of putting-out to completion of putting-out isshorter than time for the brightness increasing operation.

Appendix 3

The LED lighting apparatus as set forth in Appendix 1 or 2, wherein thefirst LED is a daylight white color LED, whereas the second LED is anincandescent color LED.

Appendix 4

The LED lighting apparatus as set forth in Appendix 2 or 3, wherein thebrightness decreasing operation from start of putting-out to completionof putting-out is performed linearly.

Appendix 5

The LED lighting apparatus as set forth in Appendix 4, wherein thebrightness decreasing operation time is half or less than the brightnessincreasing operation time.

Appendix 6

The LED lighting apparatus as set forth in Appendix 2, wherein thebrightness decreasing operation is performed rapidly immediately afterthe start of putting-out and performed slowly immediately before thecompletion of putting-out.

Appendix 7

The LED lighting apparatus as set forth in Appendix 6, wherein thebrightness decreasing operation is performed exponentially.

Appendix 8

The LED lighting apparatus as set forth in any one of Appendixes 3-5,wherein the brightness decreasing operation is performed with respect toonly the daylight white color LED.

Appendix 9

The LED lighting apparatus as set forth in Appendix any one ofAppendixes 2-8, wherein the light output controller includes a first LEDdriver for driving the first LED, a second LED driver for driving thesecond LED, and a delay unit for providing a time from the start ofputting-out to the completion of putting-out.

Appendix 10

The LED lighting apparatus as set forth in any one of Appendixes 1-9,wherein a plurality of the first LEDs and the same number of the secondLEDs are arranged on a circle.

1C Embodiment

FIGS. 22-25 show an example of LED lighting apparatus according to avariation of the present invention. The LED lighting apparatus 101C ofthis embodiment is designed for use as a ceiling light, and includes amain body 10C to be fixed to a ceiling and a remote controller 20C foroperating the main body 10C. FIG. 23 schematically shows the electricstructure of the main body 10C. FIG. 24 is an enlarged plan view of theremote controller 20C. FIG. 25 shows an example of control performed inthe LED lighting apparatus 101C.

As shown in FIG. 22, the main body 10C includes a white cover 11C, alight source unit 12C, and a power source unit 13C. The white cover 11Cis made of a milky white translucent resin and covers the light sourceunit 12C. The white cover 11C is in the form of a ring as viewed in planand exposes part of the power source unit 13C at the center. The whitecover 11C constitutes almost the entirety of the appearance of the LEDlighting apparatus 101C.

The light source unit 12C includes a plurality of LED modules 121 and122. Each LED module 121, 122 comprises an LED chip and sealing resinthat seals the LED chip and designed to emit e.g. blue light. Thesealing resin includes a fluorescent substance that emits yellow lightwhen excited by light from the LED chip, so that the light emitted fromeach LED module 121, 122 looks white. The color temperature of the whitelight emitted from each LED module depends on the LED chip and thefluorescent substance in the sealing resin. The color temperature is anindex indicating relative strength between a bluish purple ray and a redray contained in light. A higher color temperature means that a largeramount of bluish purple rays are contained, whereas a lower colortemperature means that a larger amount of red rays are contained. TheLED modules 121 are configured to emit white light of the daylight whitecolor having a color temperature of about 5000 K. The LED modules 122are configured to emit white light of the incandescent color having acolor temperature of about 3000 K. Though not illustrated, the lightsource unit 12C further includes an LED module that emits red light.This LED module is provided for use as a night light that is kept onwhen the LED modules 121 and 122 are put out.

The power source unit 13C converts e.g. AC 100V power supplied through apower supply portion provided in the ceiling to DC power suitable forlighting the LED chips and supplies the DC power to the LED modules 121,122. As shown in FIG. 23, the power source unit 13C includes a controlunit 14C, a receiver 15C and a reference Lime changer 16C.

The control unit 14C includes e.g. a capacitor, a resistor, a diode andan IC and controls electric power to be supplied to the LED modules 121,122.

The receiver 15C includes e.g. an infrared sensor and receives a controlsignal from the remote controller 20C and sends the received signal tothe control unit 14C.

As shown in FIG. 22, the reference time changer 16C is provided in thepower source unit 13C at a portion exposed from the white cover 11C. Inthis embodiment, the reference time changer 16C includes five settingbuttons 161. The five setting buttons 161 are used for changing thereference time used in the control performed in the control unit 14C.For instance, the five setting buttons 161 correspond to 0.75 sec., 1.25sec., 1.75 sec., 2.25 sec. and 2.75 sec., respectively. For instance,when the setting button 161 corresponding to 0.75 sec. is pressed, thereference time to be used in the control performed in the control unit14C is set to 0.75 sec.

The remote controller 20C corresponds to a remote controller in thevariation of the present invention and includes a transmitting portion21C, a power source button 22C, a night light button 23C, a plurality ofoperation buttons 24C, 25C, 26C, 27C, 28C. The transmitting portion 21Cincludes e.g. an LED chip that emits infrared and transmits a controlsignal to the receiver 15C when the power source button 22C, the nightlight button 23C and the operation buttons 24C, 25C, 26C, 27C, 28C arepressed. Described below is a control operation performed by the controlunit 14C when the power source button 22C, the night light button 23Cand the operation buttons 24C, 25C, 26C, 27C, 28C are pressed.

The power source button 22C is used to turn on or turn off the light.When the power source button 22C is pressed, the transmitting portion21C transmits a control signal for instructing the turn-on or turn-offoperation to the control unit 14C via the receiver 15C. In the casewhere the control signal is received when the light source unit 12C isoff, the control unit 14C performs control to turn on the LED modules121, 122 of the light source unit 12C. In the case where the controlsignal is received when the light source unit 12C is on, the controlunit 14C performs control to turn off the LED modules 121, 122 of thelight source unit 12C.

The night light button 23C is used to turn on or turn off the LED moduleof the night light. When the night light button 23C is pressed, thetransmitting portion 21C transmits a control signal for instructing theturn-on or turn-off of the LED module of the night light to the controlunit 14C via the receiver 15C. In the case where the control signal isreceived when the LED module of the night light is off, the control unit14C performs control to turn on the LED module of the night light. Inthe case where the control signal is received when the LED module of thenight light is on, the control unit 14C performs control to turn off theLED module of the night light.

The operation button 24C and the operation button 25C are brightnessadjustment buttons used for adjusting the brightness of the light sourceunit 12C and operated when the light source unit 12C is on. Forinstance, the brightness of the light source unit 12C is adjusted at thecontrol unit 14C by adjusting the electric power to be supplied to theLED modules 121, 122. The operation button 24C is used to increase thebrightness of the light source unit 12C, whereas the operation button25C is used to reduce the brightness of the light source unit 12C.

The control performed by the control unit 14 when the operation button24C is pressed is described below with reference to FIG. 25.

When the operation button 24C is pressed, the transmitting portion 21Ctransmits a control signal, indicating that the operation button 24C ispressed, to the control unit 14C via the receiver 15C. Specifically,during when the light source unit 12C is on, the control unit 14C checkswhether or not the control signal is received, in order to determinewhether or not the operation button 24C is pressed (Step S01). When thecontrol signal indicating that the operation button 24C is pressed isnot received, the control unit 14C does not perform the control forincreasing the brightness of the light source unit 12C.

Upon receiving the control signal indicating that the operation button24C is pressed, the control unit 14C measures the time elapsed since theoperation button 24C was pressed (Step S02), and compares the measuredtime with the reference time (Step S03). Specifically, the control unit14C measures the time elapsed since it started to receive the controlsignal, to find out the pressing time of the operation button 24C. Thecontrol unit 14C performs different types of control, depending onwhether or not the pressing time of the operation button 24C is longerthan the reference time. As the reference time, the time selected byusing the reference time changer 16C is used. In a default state, i.e.,when the user has not operated the reference time changer 16C, thereference time is set to 1.25 sec.

In the case where the pressing time, i.e., the time period from when theoperation button 24C was pressed till when the operation button 24C wasreleased is shorter than the reference time, the control unit 14Cdetermines that the operation button 24C was short-pressed (i.e.,pressed only for a short period of time) (Step S04). Every time theoperation button 24C is short-pressed, the control unit 14C performscontrol to increase the brightness of the light source unit 12C by onestep. Specifically, the control unit 14C increases power supply to theLED modules 121, 122 by an amount corresponding to predetermined onestep (Step S05). If the light source unit 12C is already in itsbrightest state, the control unit 14C performs control to maintain thebrightest state.

In the case where the operation button 24C is kept pressed longer thanthe reference time, the control unit 14C determines that the operationbutton 24C is long-pressed (i.e., pressed for a long period of time)(Step S06). When the operation button 24C is long-pressed in this way,the control unit 14C performs control to continuously increase thebrightness of the light source unit 12C. Specifically, the control unit14C continues to increase the power to be supplied to the LED modules121, 122 (Step S07) and stops the increasing of the power when theoperation button 24C is released (S09). According to such control,change in the brightness of the light source unit 12C stops when theuser stops pressing the operation button 24C. This ensures that the usercan easily adjust the light source unit 12C to a desired brightness.

However, when the user is long-pressing the operation button 24C, theuser's finger may unintentionally separate from the button 24C. In sucha case, the brightness of the light source unit 12C may become differentfrom the brightness which the user desired. Also, when the controlsignal is interrupted due to noise, the brightness of the light sourceunit 12C may become different from the brightness which the userdesired. To prevent this, the control described below is performed inthe present embodiment.

The determination that the long-pressing of the operation button 24C isfinished is made by the control unit 14C only when the control signalindicating the pressing of the operation button 24C is interrupted for atime period longer than a predetermined determination period. Forinstance, the determination period is 0.1 sec. That is, once theoperation button 24C is determined to be long-pressed, the determinationby the control unit 14C that the long-pressing is finished is notperformed immediately after the control signal indicating the pressingof the operation button 24C is interrupted. Specifically, after thecontrol signal indicating the pressing of the operation button 24C isinterrupted, the control unit 14C checks whether or not the controlsignal is received again within 0.1 sec. from the interruption (StepS08). In the case where the control signal is received within thedetermination period (e.g. 0.1 sec.), the control unit 14C determinesthat the operation button 24C is still long-pressed, and hence continuesto increase the power to the LED modules 121, 122. On the other hand, inthe case where the control signal is not received within thedetermination period (e.g. 0.1 sec.) from the interruption, the controlunit 14C determines that the long-pressing is finished and hence stopsthe increasing of the power to the LED modules 121, 122 (Step S09).

When the operation button 25C is pressed, the transmitting portion 21Ctransmits a control signal, indicating that the operation button 25C ispressed, to the control unit 14C via the receiver 15C. Specifically,during when the light source unit 12C is on, the control unit 14C checkswhether or not the control signal is received, in order to determinewhether or not the operation button 25C is pressed. When the controlsignal indicating that the operation button 25C is pressed is notreceived, the control unit 14C does not perform the control fordecreasing the brightness of the light source unit 12C.

Upon receiving the control signal indicating that the operation button25C is pressed, the control unit 14C measures the time elapsed since theoperation button 25C was pressed, and compares the measured time withthe reference time. Specifically, the control unit 14C measures the timeelapsed since it started to receive the control signal, to find out thepressing time of the operation button 25C. The control unit 14C performsdifferent types of control, depending on whether or not the pressingtime of the operation button 25C is longer than the reference time.Similarly to the control performed when the operation button 24C ispressed, the time selected by using the reference time changer 16C isused as the reference time. In a default state, i.e., when the user hasnot operated the reference time changer 16C, the reference time is setto 1.25 sec.

In the case where the pressing time, i.e., the time period from when theoperation button 25C was pressed till when the operation button 25C wasreleased is shorter than the reference time, the control unit 14Cdetermines that the operation button 25C was short-pressed (i.e.,pressed only for a short period of time). Every time the operationbutton 25C is short-pressed, the control unit 14C performs control todecrease the brightness of the light source unit 12C by one step.Specifically, the control unit 14C decreases power to be supplied to theLED modules 121, 122 by an amount corresponding to predetermined onestep. If the light source unit 12C is in its darkest state, the controlunit 14C performs control to maintain the darkest state.

In the case where the operation button 25C is kept pressed longer thanthe reference time, the control unit 14C determines that the operationbutton 25C is long-pressed (i.e., pressed for a long period of time).When the operation button 25C is long-pressed in this way, the controlunit 14C performs control to continuously decrease the brightness of thelight source unit 12C. Specifically, the control unit 14C continues todecrease the power to be supplied to the LED modules 121, 122 and stopsthe decreasing of the power supply when the operation button 25C isreleased. According to such control, change in the brightness of thelight source unit 12C stops when the user stops pressing the operationbutton 25C. This ensures that the user can easily adjust the lightsource unit 12C to a desired brightness.

However, when the user is long-pressing the operation button 25C, theuser's finger may unintentionally separate from the button 25C. In sucha case, the brightness of the light source unit 12C may become differentfrom the brightness which the user desired. Also, when the controlsignal is interrupted due to noise, the brightness of the light sourceunit 12C may become different from the brightness which the userdesired. To prevent this, similarly to the control performed when theoperation button 24C is pressed, the control described below isperformed in the present embodiment.

The determination that the long-pressing of the operation button 25C isfinished is made by the control unit 14C only when the control signalindicating the pressing of the operation button 25C is interrupted for atime period longer than a predetermined determination period. Forinstance, the determination period is 0.1 sec. That is, once theoperation button 25C is determined to be long-pressed, the determinationby the control unit 14C that the long-pressing is finished is notperformed immediately alter the control signal indicating the pressingof the operation button 25C is interrupted. Specifically, after thecontrol signal indicating the pressing of the operation button 25C isinterrupted, the control unit 14C checks whether or not the controlsignal is received again within 0.1 sec. from the interruption. In thecase where the control signal is received within the determinationperiod (e.g. 0.1 sec.), the control unit 14C determines that theoperation button 25C is still long-pressed, and hence continues todecrease the power to be supplied to the LED modules 121, 122. On theother hand, in the case where the control signal is not received withinthe determination period (e.g. 0.1 sec.) from the interruption, thecontrol unit 14C determines that the long-pressing is finished and hencestops the decreasing of the power supply to the LED modules 121, 122.

The operation button 26C and the operation button 27C are coloradjustment buttons used for adjusting the color of the light source unit12C and operated when the light source unit 12C is on. The operationbutton 26C is used to enhance the daylight white color, whereas theoperation button 27C is used to enhance the incandescent color. Suchadjustment of the color of the light source unit 12C is performed at thecontrol unit 14C by adjusting the ratio between the power supplied tothe LED modules 121 and the power supplied to the LED modules 122.

When the operation button 26C is pressed, the transmitting portion 21Ctransmits a control signal, indicating that the operation button 26C ispressed, to the control unit 14C via the receiver 15C. Specifically,during when the light source unit 12C is on, the control unit 14C checkswhether or not the control signal is received, in order to determinewhether or not the operation button 26C is pressed. When the controlsignal indicating that the operation button 26C is pressed is notreceived, the control unit 14C does not perform the control foradjusting the color of the light source unit 12C.

Upon receiving the control signal indicating that the operation button26C is pressed, the control unit 14C measures the time elapsed since theoperation button 26C was pressed, and compares the measured time withthe reference time. Specifically, the control unit 14C measures the timeelapsed since it started to receive the control signal, to find out thepressing time of the operation button 26C. The control unit 14C performsdifferent types of control, depending on whether or not the pressingtime of the operation button 26C is longer than the reference time.Similarly to the control performed when the operation button 24C or 25Cis pressed, the time selected by using the reference time changer 16C isused as the reference Lime. In a default state, i.e., when the user hasnot operated the reference time changer 16C, the reference time is setto 1.25 sec.

In the case where the pressing time, i.e., the time period from when theoperation button 26C was pressed till when the operation button 26C wasreleased is shorter than the reference time, the control unit 14Cdetermines that the operation button 26C was short-pressed (i.e.,pressed only for a short period of time) Every Lime the operation button26C is short-pressed, the control unit 14C performs control to enhancethe daylight white color of the light source unit 12C by one step.Specifically, the control unit 14C increases power to be supplied to theLED modules 121 by an amount corresponding to predetermined one step,while decreasing power to be supplied to the LED modules 122 by anamount corresponding to predetermined one step. By this control, the LEDmodules 121 of the daylight white color become brighter, whereas the LEDmodules 122 of the incandescent color become darker. As a result, thelight source unit 12C shows an enhanced daylight color as compared withthat before the control is performed.

In the case where the operation button 26C is kept pressed longer thanthe reference time, the control unit 14C determines that the operationbutton 26C is long-pressed (i.e., pressed for a long period of time).When the operation button 26C is long-pressed in this way, the controlunit 14C performs control to continuously enhance the daylight whitecolor of the light source unit 12C. Specifically, the control unit 14Ccontinues to increase power to be supplied to the LED modules 121, whiledecreasing power to be supplied to the LED modules 122. By this control,the LED modules 121 of the daylight white color become graduallybrighter, whereas the LED modules 122 of the incandescent color becomegradually darker. As a result, the light source unit 12C shows a moreenhanced daylight color than before the control is performed. Thisensures that the user can easily adjust the light source unit 12C to adesired color.

However, when the user is long-pressing the operation button 26C, theuser's finger may unintentionally separate from the button 26C. In sucha case, the color of the light source unit 12C may become different fromthe color which the user desired. Also, when the control signal isinterrupted due to noise, the color of the light source unit 12C maybecome different from the color which the user desired. To prevent this,similarly to the control performed when the operation button 24C or 25Cis pressed, the determination that the long-pressing of the operationbutton 26C is finished is made by the control unit 14C only when thecontrol signal indicating the pressing of the operation button 26C isinterrupted for a time period longer than a predetermined determinationperiod (e.g. 0.1 sec.).

When the operation button 27C is pressed, the transmitting portion 21Ctransmits a control signal, indicating that the operation button 27C ispressed, to the control unit 14C via the receiver 15C. Specifically,during when the light source unit 12C is on, the control unit 14C checkswhether or not the control signal is received, in order to determinewhether or not the operation button 27C is pressed. When the controlsignal indicating that the operation button 27C is pressed is notreceived, the control unit 14C does not perform the control foradjusting the color of the light source unit 12C.

Upon receiving the control signal indicating that the operation button27C is pressed, the control unit 14C measures the time elapsed since theoperation button 27C was pressed, and compares the measured time withthe reference time. Specifically, the control unit 14C measures the timeelapsed since it started to receive the control signal, to find out thepressing time of the operation button 270. The control unit 140 performsdifferent types of control, depending on whether or not the pressingtime of the operation button 27C is longer than the reference time.Similarly to the control performed when the operation button 240, 250 or260 is pressed, the time selected by using the reference time changer160 is used as the reference time. In a default state, i.e., when theuser has not operated the reference time changer 160, the reference Limeis set to 1.25 sec.

In the case where the pressing time, i.e., the Lime period from when theoperation button 270 was pressed till when the operation button 270 wasreleased is shorter than the reference time, the control unit 140determines that the operation button 27C was short-pressed (i.e.,pressed only for a short period of time). Every time the operationbutton 27C is short-pressed, the control unit 140 performs control toenhance the incandescent color of the light source unit 12C by one step.Specifically, the control unit 14C increases power to be supplied to theLED modules 122 by an amount corresponding to predetermined one step,while decreasing power supply to the LED modules 121 by an amountcorresponding to predetermined one step. By this control, the LEDmodules 122 of the incandescent color become brighter, whereas the LEDmodules 121 of the daylight white color become darker. As a result, thelight source unit 120 shows an enhanced incandescent color as comparedwith that before the control is performed.

In the case where the operation button 27C is kept pressed longer thanthe reference time, the control unit 140 determines that the operationbutton 270 is long-pressed (i.e., pressed for a long period of time).When the operation button 27C is long-pressed in this way, the controlunit 14C performs control to continuously enhance the incandescent colorof the light source unit 12C. Specifically, the control unit 14Ccontinues to increase power to be supplied to the LED modules 122, whiledecreasing power supply to the LED modules 121. By this control, the LEDmodules 122 of the incandescent color become gradually brighter, whereasthe LED modules 121 of the daylight white color become gradually darker.As a result, the light source unit 12C shows an enhanced incandescentcolor as compared with that before the control is performed. Thisensures that the user can easily adjust the light source unit 12C to adesired color.

However, when the user is long-pressing the operation button 27C, theuser's finger may unintentionally separate from the button 27C. In sucha case, the color of the light source unit 12C may become different fromthe color which the user desired. Also, when the control signal isinterrupted due to noise, the color of the light source unit 12C maybecome different from the color which the user desired. To prevent this,similarly to the control performed when the operation button 24C or 25Cis pressed, the determination that the long-pressing of the operationbutton 27C is finished is made by the control unit 14C only when thecontrol signal indicating the pressing of the operation button 27C isinterrupted for a time period longer than a predetermined determinationperiod (e.g. 0.1 sec.).

The operation button 28C is a memory button used to store the controlstate for the light source unit 12C and to reproduce the stored controlstate. When the operation button 28C is pressed, the transmittingportion 21C transmits a control signal, indicating that the operationbutton 28C is pressed, to the control unit 14C via the receiver 15C.Specifically, the control unit 14C checks whether or not the controlsignal indicating that the operation button 28C is pressed is received,in order to determine whether or not the operation button 28C ispressed.

Upon receiving the control signal indicating that the operation button28C is pressed, the control unit 14C measures the time elapsed since theoperation button 28C was pressed, and compares the measured time withthe reference time. Specifically, the control unit 14C measures the timeelapsed since it started to receive the control signal, to find out thepressing time of the operation button 28C. The control unit 14C performsdifferent types of control, depending on whether or not the pressingtime of the operation button 28C is longer than the reference time.Similarly to the control performed when the operation button 24C, 25C,26C or 27C is pressed, the time selected by using the reference timechanger 16C is used as the reference time. In a default state, i.e.,when the user has not operated the reference time changer 16C, thereference time is set to 1.25 sec.

In the case where the operation button 28C is kept pressed longer thanthe reference time, the control unit 14C determines that the operationbutton 28C is long-pressed (i.e., pressed for a long period of time). Inthis case, the control unit 14C stores the state of control with respectto the light source unit 12C. Specifically, the control unit 14C storesthe ratio between the power supplied to the LED modules 121 and thepower supplied to the LED modules 122, and the respective intensities.

In the case where the pressing time, i.e., the time period from when theoperation button 28C was pressed till when the operation button 28C wasreleased is shorter than the reference time, the control unit 14Cdetermines that the operation button 28C was short-pressed (i.e.,pressed only for a short period of time). In this case, the control unit14C reproduces the control state stored when the operation button 28C islong-pressed. Specifically, power is supplied to the LED modules 121 atthe ratio and intensity stored when the operation button 280 islong-pressed.

The remote controller 20 may have a timer function. Specifically, theremote controller 20 may be provided with a liquid crystal display forshowing the time, and an operation button for carrying out the timerfunction. For instance, by operating this operation button, the user canset the time when the light source unit 12C turns off. For instance, thetime shown on the display changes by minutes when this operation buttonis long-pressed in a manner similar to the long-pressing of theoperation buttons 240-280, and changes by hours when this operationbutton is short-pressed in a manner similar to the short-pressing of theoperation buttons 24C-28C. By using the timer function, the user can setsuch that the light source unit 12C automatically turns off at thedesired time.

The operation and advantages of the LED lighting apparatus 101C aredescribed below.

In the LED lighting apparatus 101C, the control performed by the controlunit 140 differs between when the operation button 24C-28C islong-pressed and when the operation button 24C-280 is short-pressed. Thecontrol unit 140 determines whether operation button 24C-28C islong-pressed or short-pressed by using the reference time. However,since the sense of time is different from person to person, it ispossible that the actual pressing time of the operation button isshorter than the reference time set as a default although the userthinks that they have long-pressed the operation button. It is alsopossible that the actual pressing time of the operation button is longerthan the reference time set as a default although the user thinks thatthey have short-pressed the operation button. To avoid such problems,the lighting apparatus in the present embodiment is configured such thatthe reference time can be selected from five choices by using thereference time changer 16C.

For instance, if a user often ends up short-pressing the operationbutton though having intended to long-press the operation button, thereference time set as a default is too long for the user. In such acase, inconveniences can be avoided by changing the reference time of1.25 sec. set as a default to a shorter reference time of 0.75 sec.

For instance, if a user often ends up long-pressing the operation buttonthough having intended to short-press the operation button, thereference time set as a default is too short for the user. In such acase, inconveniences can be avoided by changing the reference time of1.25 sec. set as a default to a longer reference time of 1.75 sec., 2.25sec. or 2.75 sec. Such a selectable reference time allows the user tooperate the LED lighting apparatus 101C as desired.

The LED lighting apparatus according to the variation of the inventionis not limited to the foregoing embodiment. The specific structure ofeach part of the LED lighting apparatus according to the variation ofthe invention may be varied in design in many ways. For instance,although the reference time changer 16C is provided in the main body 10Cin the above-described embodiment, the reference time changer 16C may beprovided in the remote controller 20. Although the reference timechanger 16C in the foregoing embodiment is made up of five buttons, thereference time changer may be designed such that the reference timechanges by turning a knob.

In the foregoing embodiment, control unit 14C determines that theoperation button 24C-28C has continuously been pressed when a controlsignal indicating that the operation button 24C-28C is pressed isreceived within a predetermined determination period of 0.1 sec. fromthe interruption of the control signal. However, such a determinationperiod is not limited to 0.1 sec. and may be other values.

Although the LED module 121, 122 in the foregoing embodiment comprises ablue LED chip and a sealing resin containing a fluorescent substancethat emits yellow light, an LED chip of other colors may be used. As thefluorescent substance, mixture of a fluorescent substance that emits redlight and a fluorescent substance that emits green light may be usedinstead of a fluorescent substance that emits yellow light.

In the foregoing embodiment, the light source unit 12C includes twokinds of LED modules 121 and 122 which emit white light of differentcolor temperatures, and the color of the light source unit 12C isadjusted by adjusting the intensity of the light emitted from each kindof the LED modules. However, the method of color adjustment is notlimited to this. For instance, light source unit 12C may include threekinds of LED modules that emits red light, blue light: and green light,respectively and color adjustment may be performed by adjusting theintensity of the light emitted from each of the three kinds of LEDmodules.

The feature of the present variation of the invention is described belowas Appendixes.

Appendix 1

An LED lighting apparatus comprising:

-   -   a light source unit including at least one LED chip;    -   a remote controller including one or a plurality of operation        button; and    -   a control unit that performs different kinds of control between        when the operation button is pressed longer than a predetermined        reference time and when the operation button is pressed shorter        than the reference time,    -   wherein the LED lighting apparatus further comprises a reference        time changer for changing the reference time.

Appendix 2

The LED lighting apparatus as set forth in Appendix 1, wherein:

-   -   the remote controller includes a transmitting portion for        transmitting a control signal;    -   the lighting apparatus further comprises a main body in which        the light source unit is provided and which is to be fixed to a        ceiling;    -   the main body includes a power source unit for supplying power        to the light source unit; and    -   the power source unit includes the control unit and a receiver        for receiving a signal from the remote controller.

Appendix 3

The LED lighting apparatus as set forth in Appendix 2, wherein thereference time changer is provided in the power source unit.

Appendix 4

The LED lighting apparatus as set forth in Appendix 2 or 3, wherein:

-   -   when the operation button is pressed, the transmitting portion        transmits to the receiver a control signal indicating that the        operation button is pressed; and    -   the control unit measures the time elapsed since the operation        button was pressed and compares the measured time with the        reference time.

Appendix 5

The LED lighting apparatus as set forth in Appendix 4, wherein thecontrol unit determines that the operation button is short-pressed inthe case where the time period from when the operation button waspressed till when the operation button was released is shorter than thereference time, and determines that the operation button is long-pressedin the case where the operation button is kept pressed longer than thereference time.

Appendix 6

The LED lighting apparatus as set forth in Appendix wherein:

-   -   the plurality of operation buttons include a brightness        adjustment button for adjusting brightness of the light source        unit; and    -   the control unit adjusts the brightness of the light source unit        by one step when the brightness adjustment button is        short-pressed and continuously adjusts the brightness of the        light source unit when the brightness adjustment button is        long-pressed.

Appendix 7

The LED lighting apparatus as set forth in Appendix 6, wherein thecontrol unit increases power to be supplied to the light source unit byone step when the brightness adjustment button is short-pressed andcontinuously increases power to be supplied to the light source unitwhen the brightness adjustment button is long-pressed.

Appendix 8

The LED lighting apparatus as set forth in Appendix 7, whereindetermination that long-pressing of the brightness adjustment button isfinished is made by the control unit when the control signal indicatingthat the brightness adjustment button is pressed is interrupted for aperiod longer than a predetermined determination period.

Appendix 9

The LED lighting apparatus as set forth in Appendix 7 or 8, wherein:

-   -   the plurality of operation buttons include an additional        brightness adjustment button for adjusting the brightness of the        light source unit; and    -   the control unit decreases power to be supplied to the light        source unit by one step when the additional brightness        adjustment button is short-pressed and continuously decreases        power to be supplied to the light source unit when the        additional brightness adjustment button is long-pressed.

Appendix 10

The LED lighting apparatus as set forth in Appendix 9, whereindetermination that long-pressing of the additional brightness adjustmentbutton is finished is made by the control unit when the control signalindicating that the additional brightness adjustment button is pressedis interrupted for a period longer than a predetermined determinationperiod.

Appendix 11

The LED lighting apparatus as set forth in any one of Appendixes 5-10,wherein:

-   -   the plurality of operation buttons include a color adjustment        button for adjusting color of the light source unit; and    -   the control unit adjusts the color of the light source unit by        one step when the color adjustment button is short-pressed and        continuously adjusts the color of the light source unit when the        color adjustment button is long-pressed.

Appendix 12

The LED lighting apparatus as set forth in Appendix 11, wherein:

-   -   the light source unit includes a first LED module and a second        LED module, the first LED module including a first LED chip that        is one of the plurality of LED chips and configured to emit        light of a first color temperature, the second LED module        including a second LED chip that is one of the plurality of LED        chips and configured to emit light of a second color        temperature;    -   when the color adjustment button is short-pressed, the control        unit increases power to be supplied to the first LED module by        one step and decreases power to be supplied to the second LED        module by one step; and    -   when the color adjustment button is long-pressed, the control        unit continuously increases power to be supplied to the first        LED module and continuously decreases power to be supplied to        the second LED module.

Appendix 13

The LED lighting apparatus as set forth in Appendix 12, whereindetermination that long-pressing of the color adjustment button isfinished is made by the control unit when the control signal indicatingthat the color adjustment button is pressed is interrupted for a periodlonger than a predetermined determination period.

Appendix 14

The LED lighting apparatus as set forth in Appendix 12 or 13, wherein:

-   -   the plurality of operation buttons include an additional color        adjustment button for adjusting the color of the light source        unit; and    -   when the additional color adjustment button is short-pressed,        the control unit increases power to be supplied to the second        LED module by one step and decreases power to be supplied to the        first LED module by one step; and    -   when the additional color adjustment button is long-pressed, the        control unit continuously increases power to be supplied to the        second LED module and continuously decreases power to be        supplied to the first LED module.

Appendix 15

The LED lighting apparatus as set forth in Appendix 14, whereindetermination that long-pressing of the additional color adjustmentbutton is finished is made by the control unit when the control signalindicating that the additional color adjustment button is pressed isinterrupted for a period longer than a predetermined determinationperiod.

Appendix 16

The LED lighting apparatus as set forth in any one of Appendixes 5-15,wherein:

-   -   the plurality of operation buttons include a memory button used        for storing and reproducing state of control; and    -   the control unit stores state of control when the memory button        is long-pressed and reproduces the stored state of control when        the memory button is short-pressed.

Appendix 17

The LED lighting apparatus as set forth in any one of Appendixes 1-16,wherein the reference time changer includes a plurality of settingbuttons corresponding to a plurality of different reference times.

1D Embodiment

FIGS. 27-36 show an example of LED lighting apparatus according to avariation of the present invention. The LED lighting apparatus 101D ofthe present embodiment includes a support unit 2D, a plurality ofsubstrates 3D, a plurality of LED modules 4D, a power source unit 5D, adiffusion reflection plate 6D, a light-transmitting cover 7D. The LEDlighting apparatus 101D is configured to be attached to e.g. a powersupply portion 801 in a ceiling 800 via an attachment 802 for use as aceiling light. The direction z shown in FIG. 28 is the direction fromthe floor toward the ceiling and corresponds to the axial direction inthis variation of the present invention. The lower side in the directionz in FIG. 28 is the illumination side, whereas the upper side in thedirection z in the figure is the installation side. As shown in FIG. 27,the direction x and the direction y are perpendicular to each other andalso perpendicular to the direction z. As shown in FIG. 27, the LEDlighting apparatus 101 is circular as viewed in the direction z. Thedirection perpendicular to the direction z and along the diameter of theLED lighting apparatus 101D is defined as the radial direction. In thecross section shown in FIG. 30, the radial direction is along thedirection x. In FIG. 30, on the left side, in the direction x, of thecenter line C indicated as a double-dashed line, “leftward” in thefigure corresponds to “outward” in the radial direction. On the rightside of the center line C in the direction x, “rightward” in the figurecorresponds to “outward” in the radial direction.

The support unit 2D is made of e.g. metal and in the form of a ringhaving a central axis extending in the direction z, and constitutes thesupport structure of the LED lighting apparatus 101D. As shown in FIGS.29 and 30, the support unit 2D includes a cylindrical center portion21D, an installation-side support member 22D and an illumination-sidesupport member 23D each of which is in the form of a frame surroundingthe center portion 21D, and connection portions 24D extending radiallyoutward from the center portion 21D. As shown in FIG. 30, the centerportion 21D is configured to receive the attachment 802 when the LEDlighting apparatus 101D is fixed to the ceiling 80. The power sourceunit 5D is accommodated in the lower portion of the center portion 1D inthe direction z in FIG. 30. The connection portions 24D connect thecenter portion 21D to the installation-side support member 22D and theillumination-side support member 23D.

The outer contours of the installation-side support member 22D and theillumination-side support member 23D in the radial direction define theouter contour of the support unit 2D in the radial direction, which isin the form of a polygon with 32 sides as viewed in the direction z.FIG. 31 shows the support unit 2D as enlarged. The support unit 2Dincludes 32 bends 201A corresponding to the 32 angles of the polygonforming the outer contour, and 32 straight portions 201B correspondingto the 32 sides of the polygon. The installation-side support member 22Dand the illumination-side support member 23D are 32 times symmetricalaround the central axis C. FIG. 32 shows one of the straight portions201B sandwiched between a pair of bends 201A in the direction y asenlarged. In FIGS. 31 and 32, detailed illustration of the LED module 4Dis omitted. As shown in FIG. 32, the straight portion 201A adjoins otherstraight portions 201B via the paired bends 201A. The straight portion201B shown in FIG. 32 is described below. Since other straight portions201B have rotational symmetry with respect to the straight portion 201Billustrated in FIG. 32, description as to other straight portions isomitted.

As shown in FIG. 32, the installation-side support member 22D is on theupper side with respect to the illumination-side support member 23D inthe direction z. As shown in FIG. 33, the installation-side supportmember 22D includes a pair of installation-side side plates 221, 222spaced from each other in the direction x with the substrate 3Dintervening therebetween, and an installation-side bottom plate 223. Theinstallation-side button plate 223 connects respective upper ends in thedirection z of the paired installation-side side plates 221, 222 to eachother. As shown in FIG. 33, the illumination-side support member 23Dincludes a pair of illumination-side side plates 231, 232 spaced fromeach other in the direction x with the substrate 3D interveningtherebetween, and an illumination-side bottom plate 233. Theillumination-side button plate 233 connects respective lower ends in thedirection z of the paired illumination-side side plates 231, 232 to eachother.

As shown in FIG. 34, the support unit 2D further includes a plurality ofconduction portions 25D. The conduction portions 25D are provided atmutually facing surfaces of the paired installation-side side plate 221,222 and at mutually facing surfaces of the paired illumination-side sideplates 231, 232. FIG. 35 shows three conduction portion 25D provided onthe installation-side side plate 221. As shown in FIGS. 34 and 35, eachconduction portion 25D comprises a plate portion 251 and a pair ofbulging portions 252. The plate portion 251 is made of e.g. copper andformed to cross over the bend 201A.

The paired bulging portions 252 are made of e.g. silver and spaced fromeach other across the bend 201A. As shown in FIG. 35, the conductionportions 25D are provided at respective bends 201A and spaced from eachother.

As shown in FIG. 31, each of the substrates 3D is supported on arespective one of the straight portions 201B. Thus, the plurality ofsubstrates 3D form a ring-like shape having a central axis extending inthe direction z. As shown in FIGS. 33 and 34, each of the substrates 3Dis sandwiched between the installation side bottom plate 223 and theillumination-side bottom plate 233 in the direction z. The upper end inthe direction z in FIG. 33 of each substrate 3D is sandwiched and fixedbetween the conduction portion 25D on the installation-side side plate221 and the conduction portion 25D on the installation-side side plate222. The lower and in the direction z in FIG. 33 of each substrate 3D issandwiched and fixed between the conduction portion 25D on theillumination-side side plate 231 and the conduction portion 25D on theillumination-side side plate 232. The plurality of substrates 3D, whichare mounted at different positions, have the same structure. FIG. 36shows the substrate 3D supported on the straight portion 201B positionedat the center in FIG. 32. This substrate 3D is described below.

As shown in FIG. 36, the substrate 3D is rectangular as viewed in thedirection x and includes a substrate body 31D, metal wirings 32D, 33Dformed on the substrate body 31D, and pads 34D and 35D spaced from eachother. The substrate body 31D is in the form of a plate made of aninsulating material. Suitable materials for the substrate body 31Dinclude glass-fiber-reinforced epoxy resin and ceramic material. Thesubstrate body 31D includes a support surface 311D and a bottom surface312D facing away from each other in the radial direction. The metalwirings 32D, 33D are made of e.g. copper and spaced from each other. Thepads 34D, 35D are arranged adjacent to the upper end in FIG. 36 asspaced from each other in the direction y. The pads 34D, 35D are made ofe.g. metal and in the form of a film. The pad 34D is formed on the metalwiring 32D, whereas the pad 35D is formed on the metal wiring 33D.

In the present embodiment, the dimension of the straight portion 201B inthe circumferential direction is shorter than twice the dimension of thesubstrate 3D in the circumferential direction. That is, for eachstraight portion 201B, the size that allows support of a singlesubstrate 3D is sufficient.

In the present embodiment, each substrate 3D is arranged such that itssupport surface 311D faces outward in the radial direction. Forinstance, of the three substrates 3D shown in FIG. 32, the substrate 3Din the middle is arranged such that the support surface 311D isperpendicular to the direction x. Of the three substrates 3D shown inFIG. 32, the substrate 3D on the left in the figure is arranged suchthat the support surface 311D is perpendicular to the direction inclined11.25° with respect to the direction x.

Each substrate 3D is attached to the support unit 2D by e.g. pushing oneof the ends spaced in the longitudinal direction of the substrate 3Dinto the space between the paired installation-side side plates 221 and222 and then pushing the other end of the substrate 3D into the spacebetween the illumination-side side plates 231 and 232.

The substrate 3D is arranged in each straight portion 201B such that thepad 34D is electrically connected to one of the paired bulging portions252. The pad 35D of each substrate 3D is connected to one of the pairedbulging portions 252 of the conduction portion 25D different from theconduction portion 25D to which the pad 34D is electrically connected.In other words, the pad 34D of one of two adjacent substrates 3D and thepad 35D of the other one of the two adjacent substrate 3D areelectrically connected to the same conduction portion 25D. The pads 34D,35D on the 32 substrates 3D form a single electric circuit via theconduction portion 25D provided on each bend 201A.

As shown in FIG. 31, an LED module 4D is provided on each substrate 3D.The LED modules 4D, which differ from each other in orientation, havethe same structure. The LED module 4D shown in FIG. 33 is describedbelow.

As shown in FIG. 32, the LED module 4D is supported on the supportsurface 311D. The LED module 4D is in the form of an elongated rectangleas viewed in the direction x. As shown in FIG. 33, the LED module 4Dincludes a pair of leads 41D, 42D, an LED chip 43, a sealing resin 44,and a case 45. The paired leads 41D, 42D are made of e.g. Cu alloy andspaced from each other. The LED chip 43 is mounted on the lead 41D. Ofthe lead 41D, the surface that is opposite from the surface on which theLED chip 43 is mounted is electrically connected to the metal wiring32D. The lead 42D is connected to the LED chip 43 with a wire. Thesurface of the lead 42D that is opposite from the surface connected tothe wire is electrically connected to the metal wiring 33D. The LED chip43 is the light source of the LED module 4D and designed to emit e.g.blue light. The sealing resin 44 is provided to protect LED chip 4. Thesealing resin 44 is made of a light-transmitting resin materialcontaining a fluorescent substance that emits yellow light when excitedby light from the LED chip 43. According to this structure, the LEDmodule 4D can be configured to emit light of a desired colortemperature. Instead of the fluorescent substance that emits yellowlight, mixture of a fluorescent substance that emits red light and afluorescent substance that emits green light may be used. The case 45 ismade of e.g. white resin and reflects the light traveling upward anddownward in FIG. 33 toward the left in the figure. An LED of a type thatuses two wires for connection to the paired leads 41D, 42D may beemployed as the LED chip 43.

The power source unit 5D converts e.g. AC 100 V power supplied throughthe power supply portion 801 in the ceiling 800 to DC power suitable forlighting the LED chips 43 and supplies the DC power to the LED modules4D. The power source unit 5D includes e.g. a transformer, a capacitor, aresistor, a diode and an IC.

The diffusion reflection plate 6D is made of e.g. a white resin materialthat reflects light from the LED modules 4D and arranged on theinstallation side of the support unit 2D in the direction z. As shown inFIG. 27, the outer contour of the diffusion reflection plate 6D iscircular as viewed in the direction z. The diameter of this circle issmaller than the diameter of the circle defining the outer contour ofthe LED lighting apparatus 101D. As shown in FIG. 29, the diffusionreflection plate 6D has a circular opening 61 at the center. The opening61 exposes the attachment 802 to the installation side.

The light-transmitting cover 7D constitutes most of the appearance ofthe LED lighting apparatus 101D and is made of e.g. milky-whitetranslucent resin. The light-transmitting cover 7D includes anillumination-side covering portion 71, and an installation-side coveringportion 72 which is on the installation side (upper side in FIG. 28)with respect to the illumination-side covering portion 71 in thedirection z. As shown in FIG. 27, the illumination-side covering portion71 is circular as viewed in the direction z. As shown in FIG. 30, theinstallation-side covering portion 72 extends from the outer edge of theillumination-side covering portion 71 inward in the radial direction. Asshown in FIG. 29, the installation-side covering portion 72 is formedwith a circular opening 721 at the center and in the form of a ring asviewed in the direction. The installation-side covering portion 72 ispositioned on the installation side (upper side in FIG. 3D) with respectto the diffusion reflection plate 6D in the direction z.

As shown in FIG. 30, the illumination-side covering portion 71 isinclined to be closer to the ceiling 800 in the direction z asproceeding away from the center in the radial direction. The lower edgeof the illumination-side covering portion 71 in the direction z isarranged on the illumination side (lower side in the figure) of thesupport unit 2D in the direction z. The illumination-side coveringportion 71 is dome-shaped, and at least part of the illumination-sidecovering portion 71 overlaps the LED modules 4D as viewed in the radialdirection. The diameter of the opening 721 is smaller than the diameterof the diffusion reflection plate 6D, and the diffusion reflection plate6D is exposed through the opening 721.

The advantages of the LED lighting apparatus 101D are described below.

In the present embodiment, a plurality of substrates 3D are supported assandwiched between the installation-side support member 22D and theillumination-side support member 23D which are spaced from each other inthe direction z. The contour of the installation-side support member 22Dand the contour of the illumination-side support member 23D are in theform of a polygon with 32 sides as viewed in the direction z, and thesubstrates 3D are arranged along the respective sides of the polygon.This arrangement allows the substrates 3D, which are rectangular, to bearranged evenly along the circumferential direction. Thus, the LEDlighting apparatus 101D provides uniform light emission in thecircumferential direction while using rectangular substrates 3D.

In the present embodiment, one substrate 3D is arranged on each of thestraight portions 201B. This arrangement is desirable for making eachstraight portion 201B smaller. By making each straight portion 201Bsmaller, the number of the sides of the polygon forming the outercontour of the support unit 2D can be increased. By increasing thenumber of the sides of the polygon, the contour becomes closer to acircle, which allows more uniform light emission. Although the supportunit 2D is in the form of a polygon with 32 sides in the presentembodiment, this is merely an example. By making each substrate 3Dsmaller, the support unit 2D may be made in the form of a polygon with64 sides, for example.

In the present embodiment, each substrate 3D is in the form of arelatively small rectangle. This is advantageous for cutting outsubstrates from a substrate material. When a single substrate 3D issmall, a failure in a substrate, if exists, does not lead to disposal ofa large amount of material, which is advantageous in terms of costreduction.

In the present embodiment, a plurality of LED modules 4D are arrangedsuch that each of the LED modules 40 emits light outward in the radialdirection. As shown in FIG. 30, a milky-white light-transmitting cover7D is arranged on the outer side of the LED modules 4D in the radialdirection, so that the light from the LED modules 4D is scattered by thelight-transmitting cover 7D before being emitted to the outside of thelight-transmitting cover 7D. This light illuminates the area distantfrom the LED lighting apparatus 101D in the radial direction. Moreover,part of the light from the LED modules 4D is reflected by the diffusionreflection plate 6D to be directed toward the illumination side in thedirection z and then emitted to the outside of the light-transmittingcover 7D. This light illuminates the area directly under the LEDlighting apparatus 101D. Thus, the LED lighting apparatus 101D issuitable for uniformly illuminating the interior of a room.

Generally, in an LED lighting apparatus, LED modules as the point lightsources tend to be conspicuous and look like a plurality of brightpoints. To solve such a problem, the LED lighting apparatus 101Daccording to the present embodiment is designed such that light from theLED modules 4D arranged around the support unit 2D is scattered by themilky-white light-transmitting cover 7D. Thus, when the LED lightingapparatus 101D is looked up from the floor-side, the LED lightingapparatus 101D looks as if the ring-shaped region of thelight-transmitting cover 7D surrounding the support unit 2D is emittinglight. In this way, in the LED lighting apparatus 101D, the individualLED modules 4D as the point light sources do not become too conspicuous.

Another preferred example of the substrate 3D is described below withreference to FIG. 37. In FIG. 37, the elements which are identical orsimilar to those of the substrate 3D shown in FIG. 36 are designated bythe same reference signs as those used for the substrate 3D and thedescription is appropriately omitted.

In the substrate 3D′ shown in FIG. 37, the pad 35D is arranged on theopposite side of the pad 34D in the direction z. When the substrate 3D′of this type is used, the pad 35D is electrically connected to thebulging portion 252 of the conduction portion 25D on theillumination-side side plate 231.

On the substrate 3D′ are mounted an LED module 4D and an LED module 4D′.The LED module 4D′ has basically the same structure as the LED module4D. However, the sealing resin 44 of the LED module 4D′ has a differentcomposition from that of the sealing resin 44 of the LED module 4D. Withthis arrangement, the LED module 4D and the LED module 4D′ emit light ofdifferent color temperatures. For instance, the LED module 4D may bedesigned to emit light of an incandescent color, whereas the LED module4D′ may be designed to emit light of a daylight white color.

When this substrate 3D′ is used, to light the LED modules 4D, thesubstrates 3D′ on adjacent two straight portions 201B need to bearranged in opposite orientations. For instance, when one of thesubstrates 3D′ is arranged such that the pad 34D is on the installationside in the direction z, the other substrate 3D′ needs to be arrangedsuch that the pad. 34D is on the illumination side in the direction z.By arranging the substrates 3D′ alternately in opposite orientations, anelectric circuit for lighting all the LED modules 4D is established.

In the present embodiment, conduction portions 25D are provided on boththe installation-side side plate 221 and the illumination-side sideplate 231 in order to allow the use of both types of substrates 3D andsubstrates 3D′ shown in FIGS. 36 and 37. However, when only thesubstrates 3D are to be used, the conduction portion 25D extending overthe bend 201A does not need to be provided on the illumination-side sideplate 231. For instance, instead of the conduction portions, spacers 26Dmay be provided, as shown in FIG. 38. Each spacer 26D includes a plateportion 261 and a pair of bulging portions 262 provided on the plateportion 261. As shown in FIG. 38, the plate portion 261 is arranged atthe center of the straight portion 201B. As compared with the plateportion 251 formed to extend over the bend 201A, the plate portion 261is made easily. The bulging portion 262 may be formed by soldering,which is relatively inexpensive.

Conversely, conduction portions 25D may be provided on theillumination-side side plate 231, whereas spacers 26) may be provided onthe installation-side side plate 221. In this case, the substrates 3Dare arranged such that the pads 34D, 35D are arranged on theillumination side in the direction z, in a manner reverse to thearrangement shown in FIG. 36.

Moreover, in the present embodiment, conduction portions 25D areprovided also on the installation-side side plate 222 and theillumination-side side plate 232, to adapt to the substrate 3D havingpads 34D, 35D also on the bottom surface 312D side. However, when thesubstrate 3D does not have pads 34D, 35D on the bottom surface 312Dside, conduction portions 25D do not need to be provided on theinstallation-side side plate 222 nor on the illumination-side side plate232. These conduction portions can be replaced with the spacers 26D asshown in FIG. 38.

FIGS. 39-46 show other embodiments of this variation of the presentinvention. In these figures, the elements that are identical or similarto those of the foregoing embodiments are designated by the samereference signs as those used for the foregoing embodiment.

2D Embodiment

FIGS. 39-42 show an LED lighting apparatus according to 2D embodiment ofthe variation of the present invention. The LED lighting apparatus 102Dshown in FIGS. 39-42 includes a plurality of light-transmitting member46. Other structures are the same as the LED lighting apparatus 101D.

The ht-transmitting members 46 are made of e.g. an acrylic resin andpass the light from the LED modules 4D. As shown in FIGS. 40 and 41, thelight-transmitting members 46 are arranged in the form of a ring havinga central axis extending in the direction z. The central axis of thering shape of the light-transmitting members 46 corresponds to thecentral axis of the support unit 2D. Each of the light-transmittingmembers 46 is rectangular as viewed in the radial direction. Thedimension of the light-transmitting member 46 in the circumferentialdirection is shorter than the dimension of the straight portion 201B inthe circumferential direction. That is, each of the light-transmittingmembers 46 is provided for a respective one of the straight portions201B to correspond to each substrate 3D.

FIG. 42 is a schematic cross sectional view of the LED lightingapparatus 102D along a plane perpendicular to the circumferentialdirection. As shown in FIG. 42, the light-transmitting member 46includes a bottom surface 461, a pair of side surfaces 462, 463perpendicular to the bottom surface 461, a lens surface 464 oppositefrom the bottom surface 461, and a pair of tapered surfaces 465, 466.The bottom surface 461 is in contact with the outer side surfaces of theinstallation-side side plate 221 and the illumination-side side plate231. The light-transmitting member 46 further includes a projection 461a projecting from the bottom surface 461. The projection 461 a issandwiched and supported between the installation-side side plate 221and the illumination-side side plate 231 in the direction z. Theprojection 461 a has a recess 461 b extending in the direction x. Asshown in FIG. 42, the light-transmitting member 46 is arranged to coverthe LED module 4D, and the LED module 4D is accommodated in the recess461 b.

As shown in FIG. 42, the paired side surfaces 462, 463 are spaced fromeach other in the direction z. The lens surface 464 is generally in theform of an arc in cross section and overlaps the LED module 4D as viewedin the radial direction (the direction x in FIG. 42). The lens surface464 refracts the light emitted from the LED module 4D so that the lighttravels along the direction x.

The paired tapered surfaces 465 and 466 are arranged to sandwich thelens surface 464 in the direction z. The tapered surface 465 is asurface connecting the left edge in FIG. 42 of the side surface 462 andthe upper edge in FIG. 42 of the lens surface 464 to each other, andinclined to be away from the LED module 4D in the direction z asproceeding away from the substrate 3D in the direction x. The taperedsurface 466 is a surface connecting the left edge in FIG. 42 of the sidesurface 463 and the lower edge in FIG. 42 of the lens surface 464 toeach other, and inclined to be away from the LED module 4D in thedirection z as progressing away from the substrate 3D in the directionx.

The light-transmitting member 46 is provided to protect the LED module4D and direct the light from the LED module 4D in the radial direction.The lens surface 464 is provided for causing a larger amount of lightfrom the LED module 4D to travel in the radial direction. Part of thelight emitted from LED module 4D does not reach the lens surface 464 butreaches the side surface 462, 463. Part of the light reaching the sidesurface 462 is emitted toward the installation side in the direction zand reflected by the diffusion reflection plate 6D to travel toward theillumination side in the direction z. Remaining part of the lightreaching the side surface 462 is reflected by the side surface 462 andemitted toward the illumination side in the direction z through thetapered surface 465. Since the tapered surface 465 is inclined, thelight emitted through the tapered surface 465 is bent to travel alongthe radial direction. Part of the light reaching the side surface 463 isemitted toward the illumination side in the direction z. Remaining partof the light reaching the side surface 463 is reflected by the sidesurface 463, emitted toward the installation side in the direction zthrough the tapered surface 466, and reflected by the diffusionreflection plate 6D. Since the tapered surface 466 is inclined, thelight emitted through the tapered surface 466 is bent to travel alongthe radial direction.

According to the present embodiment, the light-transmitting members 46allow the light from the LED modules 4D to be emitted uniformly towardthe light-transmitting cover 7D. Thus, the light-transmitting cover 7Dlooks bright uniformly along the circumferential direction.

According to the present embodiment, the light-transmitting member 46 isprovided at each of the straight portions 201B. Thus, eachlight-transmitting member 46 is made relatively small. If the pluralityof straight portions 201B are to be covered by a singlelight-transmitting member 46, the lens surface 464 needs to be formed ata position corresponding to each of the LED modules 4D, which requireshighly accurate working. As compared with this, covering a single LEDmodule 4D by a single light-transmitting member as in the presentembodiment leads to reduction of a production failure of thelight-transmitting member 46.

When the above-described problem is not to be taken into consideration,the light-transmitting member 46 can be designed to cover a plurality ofstraight portion 201B. FIGS. 43-45 show examples of such alight-transmitting member 46.

Shown in FIG. 43 are eight light-transmitting members 46 each of whichis formed to extend over four straight portions 201B. Thelight-transmitting members 46 shown in FIG. 43 are bent to conform tothe support unit 2D in the form of a polygon with 32 sides. Eachlight-transmitting member 46 is in contact with one of the plurality ofbends 201A. As compared with the light-transmitting members 46 shown inFIG. 41, the light-transmitting member 46 of this structure can reducethe amount of light unfavorably leaking to the outside of thelight-transmitting member 46.

The light-transmitting member 46 shown in FIG. 44 is shaped like a framein the form of polygon with 32 sides as viewed in the axial direction (zdirection) and surrounds the support unit 2D. The light-transmittingmember 46 is in contact with all the bends 201A. This light-transmittingmember 46 has an advantage that it does not easily allow the lightemitted from the LED modules 4D arranged on the straight portions 201Bto unfavorably leak to the outside.

Shown in FIG. 45 are four light-transmitting members 46 each of which isformed to extend over eight straight portions 201B. Eachlight-transmitting member 46 shown in FIG. 45 is in the form of an arcas viewed in the axial direction (direction z). This type oflight-transmitting member 46 has an advantage that it is manufacturedrelatively easily, though having a risk that a gap may be definedbetween the inner circumference of light-transmitting member 46 and thestraight portions 201B.

3D Embodiment

FIG. 46 shows an LED lighting apparatus according to 3D embodiment ofthe variation of the present invention. The LED lighting apparatus 103Dshown in FIG. 46 differs from the LED lighting apparatus 102D in shapeof the diffusion reflection plate 6D and the light-transmitting cover7D. Other structures are the same as those of the LED lighting apparatus102D. Further, in the LED lighting apparatus 103D, the connectionportions 24D are deviated toward the illumination side of the centerportion 21D in the direction z, as compared with the LED lightingapparatus 102D.

In the LED lighting apparatus 101D and the LED lighting apparatus 102D,the light-transmitting cover 7D, which is dome-shaped, is attached to arelatively flat diffusion reflection plate 6D. Unlike this, in the LEDlighting apparatus 103, the diffusion reflection plate 6D isdome-shaped, and the light-transmitting cover 7D is flat as comparedwith that of the LED lighting apparatus 101D, 102D. The diffusionreflection plate 6D in the present embodiment includes an inclinedsurface 62 which is gradually displaced toward the illumination side inthe direction z as proceeding radially outward from the center. Theinclined surface 62 overlaps the LED modules 4D as viewed in the radialdirection.

According to the present embodiment, light from each LED module 4D isreflected by the inclined surface 62 after passing through thelight-transmitting member 46, and then diffused by thelight-transmitting cover 7D. Since the diffusion reflection plate 6D ismade of white resin, light from the LED module 4D is scattered whenreflected by the inclined surface 62. This is favorable for preventingeach LED module 4D from becoming conspicuous. In the LED lightingapparatus having this arrangement, the light-transmitting cover 7D looksbright uniformly along the circumferential direction.

The LED lighting apparatus according to the variation of the inventionis not limited to the foregoing embodiment. The specific structure ofeach part of the LED lighting apparatus according to the variation ofthe invention may be varied in design in many ways.

For instance, although the installation-side support member 22D and theillumination-side support member 23D are arranged to overlap as viewedin the direction z in the present embodiment, the variation of thepresent invention is not limited to this embodiment. For instance, theinstallation-side support member 22D may be in the form of a framelarger than the illumination-side support member 23D. With thisarrangement, each substrate 3D is supported in an inclined posturebetween the installation-side support member 22D and theillumination-side support member 23D.

According to the present embodiment, fitting the substrate 3D by obliqueinsertion between the installation-side side plates 221 and 222 isexemplarily described. However, the substrate 3D can be placed by othermethods. For instance, each bend 201A may be provided with a slitbetween the installation-side side plate 221 and the illumination-sideside plate 231 so that the substrate 3D can be inserted through theslit.

Although each LED module 4D includes a single LED chip 43 in the presentembodiment, each LED module 4D may include tow or more LED chips 43.Further, three or more LED modules 4D may be mounted on the substrate3D. When a plurality of LED modules 4D are mounted on the substrate 3D,LED modules 4D that emit light of different color temperatures may beused in various combinations.

Although a single substrate 3D is supported on each straight portion201B in the present embodiment, this variation of the invention is notlimited to such a structure. That is, even when a plurality ofsubstrates 3D are supported on each straight portion 201B, uniformillumination in the circumferential direction can be achieved as long asthe number of sides of a polygon defining the contour of the supportunit 2D is sufficiently large.

The feature of the present variation of the invention is described belowas Appendixes.

Appendix 1

An LED lighting apparatus comprising:

-   -   a plurality of LED chips;    -   a plurality of substrates supporting the LED chips;    -   a support unit in the form of a ring supporting the substrates;        and    -   a light-transmitting cover at least part of which is on an        illumination side of the support unit which is one side in a        direction of an axis of the support unit, the light-transmitting        cover being configured to transmit light from the LED chips,        wherein:    -   the plurality of substrates are arranged in the form of a ring        having an axis corresponding to the axis of the support unit,    -   each of the substrates includes a support surface facing an        outer side which is one side in a radial direction of the        support unit,    -   each of the support surfaces supports a respective one of the        LED chips,    -   the support unit includes a plurality of conduction portions, an        illumination-side support member, and an installation-side        support member arranged on an installation side with respect to        the illumination-side support member, which is the other side in        said direction of the axis,    -   the illumination-side support member includes a pair of        illumination-side side plates spaced from each other in the        radial direction with the substrates intervening therebetween,        and    -   the installation-side support member includes a pair of        installation-side side plates spaced from each other in the        radial direction with the substrates intervening therebetween.

Appendix 2

The LED lighting apparatus as set forth in Appendix 1, wherein:

-   -   the illumination-side support member further includes an        illumination side bottom plate connecting respective ends of the        paired illumination-side side plates on the illumination side in        said direction of the axis to each other,    -   the installation-side support member further includes an        installation-side bottom plate connecting respective ends of the        paired installation-side side plates on the installation side in        said direction of the axis to each other, and    -   the substrates are positioned between the illumination-side        bottom plate and the installation-side bottom plate in said        direction of the axis.

Appendix 3

The LED lighting apparatus as set forth in Appendix 1 or 2, wherein eachof the substrates is rectangular as viewed in the radial direction.

Appendix 4

The LED lighting apparatus as set forth in Appendix 3, wherein:

-   -   each of the substrates is provided with a first pad and a second        pad that are spaced from each other, and    -   each of the conduction portions electrically connects the first        pad of one of adjacent substrates and the second pad of the        other one of the adjacent substrates to each other.

Appendix 5

The LED lighting apparatus as set forth in Appendix 4, wherein:

-   -   the support unit has a polygonal contour as viewed in said        direction of the axis,    -   the support unit includes a plurality of bends at positions        corresponding to angles of the polygon of the contour and a        plurality of straight portions at positions corresponding to        sides of the polygon of the contour,    -   the straight portions include a first straight portion and a        second straight portion adjoining each other with a first bend        that is one of the plurality of bends intervening therebetween,        and    -   the plurality of substrates include a first substrate supported        on the first straight portion and a second substrate supported        on the second straight portion.

Appendix 6

The LED lighting apparatus as set forth in Appendix wherein each of thestraight portions has a dimension in a circumferential direction that isshorter than twice a dimension of each of the substrates in acircumferential direction.

Appendix 7

The LED lighting apparatus as set forth in Appendix 6, wherein each ofthe conduction portions is provided to cross over each of the bends.

Appendix 8

The LED lighting apparatus as set forth in Appendix 7, wherein theconduction portions are provided on the installation-side supportmember.

Appendix 9

The LED lighting apparatus as set forth in Appendix 7, wherein:

-   -   the conduction portions include a first conduction portion that        electrically connects the first pad of the first substrate and        the second pad of the second substrate to each other, and a        second conduction portion electrically connected to the second        pad of the first substrate,    -   the first conduction portion is provided on the        installation-side support member, and    -   the second conduction portion is provided on the        illumination-side support member.

Appendix 10

The LED lighting apparatus as set forth in Appendix 7, wherein each ofthe conduction portions is provided on the illumination-side supportmember.

Appendix 11

The LED lighting apparatus as set forth in any one of Appendixes 5-10,further comprising a plurality of light-transmitting members arranged inthe form of a zing having an axis corresponding to said axis,

-   -   wherein the light-transmitting members include a first        light-transmitting member covering a first LED chip that is one        of the LED chips.

Appendix 12

The LED lighting apparatus as set forth in Appendix 11, wherein thefirst light-transmitting member includes a lens surface that overlapsthe first LED chip as viewed in the radial direction.

Appendix 13

The LED lighting apparatus as set forth in Appendix 12, wherein:

-   -   the first light-transmitting member includes a pair of tapered        surfaces arranged to sandwich the lens surface in said direction        of the axis, and    -   each of the tapered surfaces is inclined to be away from the        first LED chip in the radial direction as proceeding away from        the lens surface in said direction of the axis.

Appendix 14

The LED lighting apparatus as set forth in any one of Appendixes 11-13,wherein each of the light-transmitting members has a dimension in acircumferential direction that is shorter than a dimension of each ofthe straight portions in a circumferential direction.

Appendix 15

The LED lighting apparatus as set forth in any one of Appendixes 11-13,wherein each of the light-transmitting members has a curved shape toconform to the support unit.

Appendix 16

The LED lighting apparatus as set forth in any one of Appendixes 11-13,wherein each of the light-transmitting members is in the form of an arcas viewed in said direction of the axis.

Appendix 17

The LED lighting apparatus as set forth in any one of Appendixes 5-10,further comprising a light-transmitting member in the form of a ringhaving an axis corresponding to said axis,

-   -   wherein the light-transmitting member surrounds the support        unit.

Appendix 18

The LED lighting apparatus as set forth in Appendix 17, wherein thelight-transmitting member includes a lens surface overlapping a firstLED chip that is one of the LED chips, as viewed in the radialdirection.

Appendix 19

The LED lighting apparatus as set forth in Appendix 18, wherein:

-   -   the light-transmitting member includes a pair of tapered        surfaces arranged to sandwich the lens surface in said direction        of the axis, and    -   each of the tapered surfaces is inclined to be away from the        first LED chip in the radial direction as proceeding away from        the lens surface in said direction of the axis.

Appendix 20

The LED lighting apparatus as set forth in Appendix 19, wherein thelight-transmitting member has a polygonal shape extending along thesupport unit.

Appendix 21

The LED lighting apparatus as set forth in any one of Appendixes 1-20,wherein the light-transmitting cover is made of milky-white translucentresin.

Appendix 22

The LED lighting apparatus as set forth in any one of Appendixes 1-21,further comprising a diffusion reflection plate at least part of whichis arranged on the installation side of the support unit in saiddirection of the axis.

Appendix 23

The LED lighting apparatus as set forth in Appendix 22, wherein thediffusion reflection plate is made of white resin.

Appendix 24

The LED lighting apparatus as set forth in Appendix 23, wherein:

-   -   the diffusion reflection plate includes an inclined surface that        is gradually displaced toward the illumination side in said        direction of the axis as proceeding away from a center in the        radial direction, and    -   the inclined surface overlaps one of the LED chips as viewed in        the radial direction.

Appendix 25

The LED lighting apparatus as set forth in any one of Appendixes 21-23,wherein at least part of the light-transmitting overlaps one of the LEDmodules as viewed in the radial direction.

1E Embodiment

FIGS. 48 and 49 show an LED lighting apparatus according to 1Eembodiment of the variation of the present invention. The LED lightingapparatus 101E of the present embodiment includes a support unit 20E, aplurality of light source units 30E, a diffusion reflection plate 40E, apower source unit 50, a cover 60, and a light-transmitting plate 70. TheLED lighting apparatus 101E is designed for use as a ceiling light, andincludes an attachment 802 for attaching the LED lighting apparatus to apower supply portion in a ceiling 800, for example. The direction zshown in FIG. 49 is the direction from the ceiling toward the floor andcorresponds to the first direction in this variation of the presentinvention. The lower side in the direction z in FIG. 49 is theillumination side, whereas the upper side in the direction z in thefigure is the installation side. The direction r shown in FIGS. 48 and49 is the radial direction with respect to the axial direction z andcorresponds to the second direction in this variation of the presentinvention. As shown in FIG. 48, the LED lighting apparatus 101 iscircular as viewed in the direction z.

The support unit 20E is made of a metal such as aluminum and constitutesthe support structure of the LED lighting apparatus 101E. The supportunit 20E is in the form of an equilateral octagon as viewed in thedirection z, but is not limited to this shape. The support unit 20Eincludes eight side plates 21E respectively extending along the eightsides of the octagon. The center of the support unit 20E corresponds tothe center of the LED lighting apparatus 101E. The eight side plates 21Epartition between the outer side, which is one side in the direction r,and the inner side, which is the other side in the direction r. Eachside plate 21E is inclined to be gradually displaced outward in thedirection r as proceeding from the illumination side toward theinstallation side in the direction z. A space for accommodating thepower source unit 50 is provided on the inside of the side plates 21E inthe direction r. The support unit 20E as a whole is in the form of aring as viewed in the direction z and receives in it the attachment 802when the LED lighting apparatus 101E is fixed to the ceiling 800.

The light source units 30E are placed on the outer surfaces of the sideplates 21E of the support unit 20E in the direction r. Each light sourceunit 30E includes a substrate 31E, a plurality of LED modules 32E and aprotective member 33E. The substrate 31 is an insulating substrate madeof e.g. glass-fiber-reinforced epoxy resin. The protective member 33E ismade of e.g. transparent acrylic resin and covers the LED modules 32E.For instance, the protective member 33E is generally in the form of ahalf tube having a semicircular cross section.

The LED modules 32E are mounted on the substrate 31E. As shown in FIG.50, each LED module 32E includes a pair of leads 321E, an LED chip 322E,a sealing resin 323 and a case 324. The paired leads 321E are made ofe.g. Cu alloy. The LED chip 322E is mounted on one of the leads 321E.The surfaces of the leads 321E opposite from the surface on which theLED chip 322E is mounted serve as mounting terminals 325 forsurface-mounting the LED module 32E. The LED chip 322E is the lightsource of the LED module 32E and is configured to emit e.g. blue light.The sealing resin 323 protects the LED chip 322E. The sealing resin 323is made of a light-transmitting resin material containing a fluorescentsubstance that emits yellow light when excited by light from the LEDchip 322E. According to this structure, the LED module 32E can beconfigured to emit light of a desired color temperature. Instead of thefluorescent substance that emits yellow light, mixture of a fluorescentsubstance that emits red light and a fluorescent substance that emitsgreen light may be used. The case 324 is made of e.g. white resin andreflects the light traveling toward the sides from the LED chip 322E inthe upward direction. An LED of a type that uses two wires forconnection to the paired leads 321E may be employed as the LED chip322E.

The light-transmitting cover 70 constitutes most of the appearance ofthe LED lighting apparatus 101E as seen from the illumination side inthe direction z and is made of e.g. milky-white translucent resin. Thelight transmitting plate 70 is in the form of a ring as viewed in thedirection z and positioned on the illumination side in the direction zwith respect to the light source units 30E. Light traveling from thelight source units 30E to the light-transmitting plate 70 passes throughthe light-transmitting plate 70 while being diffused by the lighttransmitting plate 70. The light is then emitted through theillumination-side surface in the direction z of the light-transmittingplate 70. In the present embodiment, the thickness of thelight-transmitting plate 70 reduces as proceeding outward in thedirection r.

The cover 60 is arranged on the illumination side of the support unit20E in the direction z. The cover 60 is made of e.g. aluminum or a resinand circular as viewed in the direction z. In the present embodiment,the light transmitting plate 70 is fixed, along with the cover 60, tothe support unit 20E by using bolts. With this arrangement, thelight-transmitting plate 70 is removably attached to the support unit20E.

The diffusion reflection plate 40E is made of e.g. a white resinmaterial that reflects light from the LED modules 32E and arranged onthe installation side of the support unit 20E in the direction z. Asshown in FIG. 48, the outer contour of the diffusion reflection plate40E is circular as viewed in the direction z. The diameter of thiscircle is smaller than the diameter of the light-transmitting plate 70.As shown in FIG. 49, the diffusion reflection plate 40E has a circularopening 41E at the center. The opening 41E exposes the attachment 802 tothe installation side. The diffusion reflection plate 40E furtherincludes a peripheral portion 42E, The peripheral portion 42E isinclined to be gradually displaced toward the illumination side in thedirection z as proceeding outward in the direction r.

The power source unit 50 converts e.g. commercial AC of 100 V to DCpower suitable for lighting the LED chips 322E. The power source unit 50includes e.g. a transformer, a capacitor and an LED driver.

FIG. 51 shows an example of use of the LED lighting apparatus 101E. Inthis example, the LED lighting apparatus 101E further includes anextension adapter 803 as a structural part. The extension adapter 803includes a first intermediate fitting portion 804, a second intermediatefitting portion 805, and a cable 806. The first intermediate fittingportion 804 is configured to be attachable to the power supply portion801 of the ceiling 800. The second intermediate fitting portion 805 isconfigured to be attachable to the attachment 802. The cable 806connects the first intermediate fitting portion 804 and the secondintermediate fitting portion 805 to each other. The power supply portion801 and the attachment 802 are electrically connected to each other viathe extension adapter 803. Moreover, in this example of use, alight-transmitting plate 70 having a smaller diameter than that shown inFIG. 48 is used. In this example, the LED lighting apparatus 101E isused as a so-called pendant light for illuminating e.g. a table from aposition spaced downward in the direction z from the ceiling 800.

FIG. 52 shows the state where the light-transmitting plate 70 isdetached from the LED lighting apparatus 101E in the example of useshown in FIG. 48. By removing the bolts as shown in the figure, thelight-transmitting plate 70 can be detached along with the cover 60.FIG. 53 shows how to attach the LED lighting apparatus for achieving theuse shown in FIG. 51. First, a light-transmitting plate 70 smaller thanthe light-transmitting plate 70 shown in FIG. 48 and an extensionadapter 803 are prepared. Then, the extension adapter 803 is mounted tothe power supply portion 301 and to the attachment 802. Then, by usingthe bolts shown in the figure, the light-transmitting plate 70 isattached to the support unit 20E, along with the cover 60. By this, theLED lighting apparatus 101E in the example of use shown in FIG. 51 iscompleted.

The advantages of the LED lighting apparatus 101E are described below.

According to the present embodiment, as shown in 49, the portion nearthe outer periphery of the LED lighting apparatus 1015 in the directionr comprises only the thickness of the light-transmitting plate 7,whereby the appearance of the LED lighting apparatus 101E is enhanced.Since the light-transmitting plate 70 has a smaller thickness at anouter portion in the direction r, the LED lighting apparatus 101E has asmaller thickness at the outer periphery. The amount of light from thelight source units 305 reaching the light-transmitting plate 70 issmaller at a portion farther from the light source units 30E. Since thelight-transmitting plate 70 is thinner at an outer portion in thedirection r, relatively bright light can be emitted through the outerportion even when the amount of light reaching there is small. Thus, theentirety of the light-transmitting plate 70 is uniformly illuminated.

As shown in FIGS. 49 and 51, by selectively using the extension adapter803, the LED lighting apparatus 101E can be used either as a ceilinglight or a pendant light as desired. Since the light-transmitting plate70 is configured to be detachable from the support unit 20E, alight-transmitting plate 70 of a size suitable for a ceiling light or apendant light can be employed as desired.

FIGS. 54-64 show other examples and embodiments of the presentvariation. In these figures, the elements that are identical or similarto those of the foregoing embodiment are designated by the samereference signs as those used for the foregoing embodiment.

FIG. 54 shows another example of the diffusion reflection plate 40E ofthe LED lighting apparatus 101E. In this example, the peripheral portion42E of the diffusion reflection plate 40E comprises a corrugated plate.With this arrangement, the heat conducted from the light source units30E to the support unit 20E and the diffusion reflection plate 40E isefficiently dissipated from the peripheral portion 42E.

FIG. 55 shows another example of the diffusion reflection plate 40E ofthe LED lighting apparatus 101E. In this example, the peripheral portion42E of the diffusion reflection plate 40E is formed with a plurality ofgrooves 421. With this example again, the heat conducted from the lightsource units 30E to the support unit 20E and the diffusion reflectionplate 40E is efficiently dissipated from the peripheral portion 42E.

FIG. 56 shows another example of the diffusion reflection plate 40E ofthe LED lighting apparatus 101E. In this example, the diffusionreflection plate 40E comprises a substrate 401 and an anodized aluminumlayer 402. The substrate 401 is made of aluminum. The anodized aluminumlayer 402 is formed by performing anodizing with respect to thesubstrate 401. With this example again, heat from the light source units30E is efficiently dissipated.

FIG. 57 shows another example of the diffusion reflection plate 40E ofthe LED lighting apparatus 101E. In this example, the diffusionreflection plate 40E comprises a substrate 401 and a highlyheat-dissipative coating 403. The substrate 401 is made of a metal suchas aluminum. The highly heat-dissipative coating layer 403 is formed byapplying a highly heat-dissipative paint to the substrate 401. Examplesof such highly heat-dissipative paint include white paint containing aceramic material such as alumina or metal particles. With this exampleagain, heat from the light source units 30E is efficiently dissipated.

2E Embodiment

FIGS. 58 and 59 show an LED lighting apparatus according to 2Eembodiment of the variation of the present invention. The LED lightingapparatus 102E of the present embodiment includes a support unit 20E, aplurality of light source units 30E, a plurality of additional lightsource units 30E′, a power source unit 50 and a light guide 80.Similarly to the LED lighting apparatus 101E shown in FIG. 48, the LEDlighting apparatus 102E as a whole is circular as viewed in thedirection z.

The support unit 20E is made of a metal such as aluminum and constitutesthe support structure of the LED lighting apparatus 102E. The supportunit 20E is in the form of an equilateral octagon as viewed in thedirection z, but is not limited to this shape. The support unit 20Eincludes eight side plates 21E respectively extending along the eightsides of the octagon, and eight engagement portions 22E. The center ofthe support unit 20E corresponds to the center of the LED lightingapparatus 102E. The eight side plates 21E partition between the outerside, which is one side in the direction r, and the inner side, which isthe other side in the direction r. Each side plate 21E is inclined to begradually displaced inward in the direction r as proceeding from theillumination side toward the installation side in the direction z. Thesupport unit 20E as a whole is in the form of a ring as viewed in thedirection z and receives in it the attachment 802 when the LED lightingapparatus 102E is fixed to the ceiling 800. The engagement portions 22Eextend from the lower ends of the side plates 21E in the direction z andhold the light guide 80.

The light source units 30E are placed on the outer surfaces of the sideplates 21E of the support unit 20E in the direction r. Each light sourceunit 30E includes a substrate 31E and a plurality of LED modules 32E.The structures of the substrate 31E and the LED modules 32E are asdescribed above.

The power source unit 50 converts e.g. commercial AC of 100 V to DCpower suitable for lighting the LED chips 322E. The power source unit 50includes e.g. a transformer, a capacitor and an LED driver and issupported by the support unit 20E.

The light guide 80 is made of e.g. transparent acrylic resin and is inthe form of a ring as viewed in the direction z. The light guide 80includes a constricted portion 81, a bent portion 82, and a ring plateportion 83. The constricted portion 81 is an inner portion of the lightguide 80 in the direction r, and includes a recess 811, an incidentsurface 812, and a bottom surface 813, as shown in FIG. 59. The bottomsurface 813 faces the substrate 31E of the light source unit 30E and canbe in contact with the substrate 31E. The constricted portion 81 has across section that reduces as proceeding from the bottom surface 813 inthe direction in which the substrate 31E faces. The recess 811 is formedin the bottom surface 813 and accommodates the LED module 32E of thelight source unit 30E. The incident surface 812 is part of the innersurface of the recess 811 and faces the LED module 32E.

The bent portion 82 is connected to the outer side in the direction r ofthe constricted portion 81 and bent as shown in FIG. 59. The ring plateportion 83 is connected to the outer side in the direction r of the bentportion 82 and comprises a plate in the form of a ring as viewed in thedirection z. The ring plate portion 83 is connected to the constrictedportion 81 via the bent portion 82 so that the ring plate portion 83 ispositioned on the installation side in the direction z with respect tothe light source units 30E. A reflective layer 84 is placed on theinstallation side in the direction z of the ring plate portion 83. Thereflective layer 84 is made of white resin or aluminum. The surface ofthe ring plate portion 83 on the illumination side in the direction zconstitutes an emission surface 832. As shown in FIG. 58, the outer edgeof the ring plate portion 83 in the direction r is covered with alight-shielding member 87. The light-shielding member 87 is in the formof a ring that is U-shaped in cross section and made of opaque resin ormetal.

As shown in FIG. 59, light emitted from the LED module 32E impinges onthe incident surface 812 and then travels through the constrictedportion 81 toward the bent portion 82. The light is totally reflected inthe bent portion 82 and hence travels toward the ring plate portion 83.In the ring plate portion 83, light travels toward the outer portion inthe direction r of the ring plate portion 83. During this process, partof the light reflected by the reflective layer 84 is emitted from theemission surface 832 toward the illumination side in the direction z, asshown in FIG. 58. The light reaching the outer edge of the ring plateportion 83 in the direction r is prevented, by the light-shieldingmember 87, from traveling further outward in the direction r.

The additional light source units 30E′ are placed on the inner surfacesof the side plates 21E. Each additional light source unit 30E′ includesa substrate 31E and a plurality of LED modules 32E, and has the samestructure as that of the light source unit 30E.

The advantages of the LED lighting apparatus 102E are described below.

According to the present embodiment, the thickness of the LED lightingapparatus 102E is almost the same as the thickness of the ring plateportion 83 of the light guide 80, except at the center in the directionr, and hence, the lighting apparatus is snugly fitted to the ceiling800.

Thus, the LED lighting apparatus 102E does not project largely from theceiling 800. This enhances the appearance of the room in which thelighting is attached.

Since the LED module 32E is accommodated in the recess 811, light fromthe LED module 32E is prevented from leaking from the light guide 80.Since the incident surface 812 faces the LED module 32E, a large amountof light from the LED module 32E impinges on the incident surface 812.The bottom surface 813 which faces the substrate 31E and which can be incontact with the substrate 31E is advantageous for preventing leakage oflight from the light guide 80.

The constricted portion 81 has the effect of converging light from theLED module 32E toward the bent portion 82. The bent portion 82 serves toreflect the light, traveling from the constricted portion 81, towardring plate portion 83. The provision of the bent portion 82 allows thering plate portion 83 to be positioned on the installation side in thedirection z with respect to the light source units 30E.

The reflective layer 84 prevents the light, traveling through the ringplate portion 83, from leaking toward the installation side in thedirection z, and reflects the light toward the emission surface 832.

FIG. 60 shows another example of the LED lighting apparatus 102E. TheLED lighting apparatus 102E of this example includes alight-transmitting cover 75 and a reflective cover 76. Thelight-transmitting cover 75 is made of e.g. milky-white translucentresin and provided on the inner side of the support unit 20E to coverthe additional light source units 30E°. The reflective cover 76 is madeof e.g. white resin or aluminum. The reflective cover 76 is arranged onthe inner side with respect to the additional light source units 30E° inthe direction r and covers the attachment 802.

With this example again, the LED lighting apparatus 1025 provides goodappearance. Since the additional light source units 30E′ are provided,almost entire surface of the LED lighting apparatus 102E looks brightwhen the LED lighting apparatus 102E is looked up from the illuminationside in the figure. The provision of the reflective cover ensures that alarger amount of light from the additional light source units 30E′ isemitted to the outside through the light-transmitting cover 75. Thestructure including the light-transmitting cover 75 is advantageous forachieving uniform light emission.

FIGS. 61-64 show other examples of the light guide 80 of the LEDlighting apparatus 102E.

In the example shown in FIG. 61, a wall portion 86 is provided on theinstallation side of the ring plate portion 83 in the direction z. Thewall portion 86 is made of e.g. sponge or resin and held in contact withthe ring plate portion 83 and the ceiling 80. In this example, thereflective layer 84 is not provided on the outer side of the wallportion 86 in the direction r. The surface of the ring plate portion 83that is exposed toward the installation side in the direction z providesthe emission surface 833. With this example, the wall portion 86prevents dust or the like from being accumulated on the installationside of the ring plate portion 83 in the direction z. Moreover, theceiling 800 is slightly illuminated with light emitted from the emissionsurface 833.

In the example shown in FIG. 62, a reflective layer 84 and a black layer85 are formed on the installation side of the ring plate portion 83 inthe direction z. The reflective layer 84 is made of metal such asaluminum. The black layer 85 is formed by applying a black paint orcomprises a black resin sheet. The reflective layer 84 and the blacklayer 85 extend to a position close to the outer edge of the ring plateportion 83 in the direction r. According to this example, owing to theprovision of the black layer 85, the image of the LED lighting apparatus102E is unlikely to appear on the ceiling 800. This is suitable formaking the LED lighting apparatus 102E look compact.

In the example shown in FIG. 63, the reflective layer 84 and the blacklayer 85 are formed to reach the wall portion 86. The surface of thering plate portion 83 that is exposed toward the installation side inthe direction z provides the emission surface 833, whereas the outer endsurface of the ring plate portion 83 in the direction r provides theemission surface 834. In this example, all the emission surfaces 832,833 and 834 comprise rough surfaces. This arrangement is suitable formaking the portion of the LED lighting apparatus 102E near the outeredge in the direction r brighter. The emission surfaces 832, 833, 834comprising rough surface promote uniform light emission.

In the example shown in FIG. 64, the ring plate portion 83 includes acurved outer periphery 831. The curved outer periphery 831 is curved tobe gradually displaced toward the illumination side in the direction zas proceeding radially outward in the direction r. In this example, theend surface of the curved outer periphery 831 faces the illuminationside in the direction z. The outer surface of the curved outer periphery831 in the direction r provides the emission surface 833 which comprisesa rough surface. With this example again, the portion of the LEDlighting apparatus 102E near the outer edge in the direction r can bemade bright.

The LED lighting apparatus according to the variation of the inventionis not limited to the foregoing embodiment. The specific structure ofeach part of the LED lighting apparatus according to the variation ofthe invention may be varied in design in many ways.

The feature of the present variation of the invention is described belowas Appendixes.

Appendix 1

An LED lighting apparatus comprising:

-   -   a light source unit including at least one LED chip;    -   a support unit supporting the light source unit; and    -   a light-transmitting plate at least part of which is on an        illumination side, which is one side in a first direction, of        the support unit, the light-transmitting plate being configured        to transmit light from the light source unit, wherein:    -   the support unit includes a plurality of side plates        partitioning between an outer side, which is one side in a        second direction corresponding to a radial direction with        respect to an axial direction corresponding to the first        direction, and an inner side, which is the other side in the        second direction,    -   the inner side in the second direction is surrounded by the        plurality of side plates,    -   each of the side plates is inclined to be gradually displaced        outward in the second direction as proceeding from the        illumination side toward an installation side opposite from the        illumination side in the first direction,    -   the light source unit is arranged on an outer surface in the        second direction of one of the side plates, and    -   the light-transmitting plate is in the form of a ring arranged        on the illumination side in the first direction with respect to        the light source unit.

Appendix 2

The LED lighting apparatus as set forth in Appendix 1, wherein thelight-transmitting plate is removably attached to the support unit.

Appendix 3

The LED lighting apparatus as set forth in Appendix 2, wherein thelight-transmitting plate becomes thinner as proceeding outward in thesecond direction.

Appendix 4

The LED lighting apparatus as set forth in Appendix 2 or 3, furthercomprising a cover for attaching the light-transmitting plate to thesupport unit.

Appendix 5

The LED lighting apparatus as set forth in any one of Appendixes 2-4,further comprising:

-   -   an attachment for mounting the LED lighting apparatus to a power        supply portion provided externally of the LED lighting        apparatus; and    -   an extension adapter including a first intermediate fitting        portion to be attached to the power supply portion, a second        intermediate fitting portion to be attached to the attachment,        and a cable connecting the first intermediate fitting portion        and the second intermediate fitting portion to each other.

Appendix 6

The LED lighting apparatus as set forth in any one of Appendixes 1-5,further comprising a diffusion reflection plate that is arranged on theinstallation side of the support unit in the first direction andreflects light from the light source unit.

Appendix 7

The LED lighting apparatus as set forth in Appendix 6, wherein thediffusion reflection plate includes a peripheral portion positioned inan outer region in the second direction and inclined to be graduallydisplaced toward the illumination side in the first direction asproceeding outward in the second direction.

Appendix 8

The LED lighting apparatus as set forth in Appendix 7, wherein theperipheral portion comprises a corrugated plate.

Appendix 9

The LED lighting apparatus as set forth in Appendix 7, wherein theperipheral portion includes a plurality of grooves.

Appendix 10

The LED lighting apparatus as set forth in any one of Appendixes 6-9,wherein the diffusion reflection plate is made of aluminum with ananodized surface.

Appendix 11

The LED lighting apparatus as set forth in any one of Appendixes 7-9,wherein the outer periphery has a highly heat-dissipative coating.

Appendix 12

An LED lighting apparatus comprising:

-   -   a light source unit including at least one LED chip; and    -   a support unit supporting the light source unit, wherein:    -   the support unit includes a plurality of side plates        partitioning between an outer side, which is one side in a        second direction corresponding to a radial direction with        respect to an axial direction corresponding to a first        direction, and an inner side, which is the other side in the        second direction,    -   the inner side in the second direction is surrounded by the        plurality of side plates,    -   each of the side plates is inclined to be gradually displaced        inward in the second direction as proceeding from the        illumination side toward an installation side opposite from the        illumination side in the first direction,    -   the light source unit is arranged on an outer surface in the        second direction of one of the side plates, and    -   the LED lighting apparatus further comprises a light guide        including an incident surface on which light from the light        source unit becomes incident and a ring plate portion positioned        on the installation side in the first direction with respect to        the incident surface, a surface of the ring plate portion that        is on the illumination side in the first direction providing an        emission surface.

Appendix 13

The LED lighting apparatus as set forth in Appendix 12, wherein: thelight guide includes a recess accommodating the LED chip, and

-   -   the recess includes an inner surface part of which constitutes        the incident surface.

Appendix 14

The LED lighting apparatus as set forth in Appendix 13, wherein: thelight source unit includes a substrate on which the LED chip is mounted,

-   -   the light guide includes a bottom surface facing the substrate,        and    -   the recess is formed in the bottom surface.

Appendix 15

The LED lighting apparatus as set forth in Appendix 14, wherein thelight guide includes a constricted portion having a cross section thatreduces as proceeding from the bottom surface in a direction in whichthe substrate faces.

Appendix 16

The LED lighting apparatus as set forth in Appendix 15, wherein thelight guide includes a bent portion connecting the constricted portionand the ring plate portion to each other.

Appendix 17

The LED lighting apparatus as set forth in Appendix 15 or 16, whereinthe support unit includes an engagement portion that engages theconstricted portion of the light guide at a portion on the illuminationside in the first direction.

Appendix 18

The LED lighting apparatus as set forth in any one of Appendixes 12-17,further comprising a light-shielding member covering an outer edge ofthe ring plate portion.

Appendix 19

The LED lighting apparatus as set forth in any one of Appendixes 12-18,further comprising a reflective layer covering the ring plate portion onthe installation side in the first direction.

Appendix 20

The LED lighting apparatus as set forth in Appendix 19, furthercomprising a black layer covering the reflective layer on theinstallation side in the first direction.

Appendix 21

The LED lighting apparatus as set forth in any one of Appendixes 12-20,wherein the ring plate portion includes a curved outer periphery curvedto be gradually displaced toward the illumination side in the firstdirection as proceeding outward in the second direction.

Appendix 22

The LED lighting apparatus as set forth in any one of Appendixes 12-21,further comprising a wall portion projecting from the ring plate portiontoward the installation side in the first direction.

Appendix 23

The LED lighting apparatus as set forth in any one of Appendixes 12-22,further comprising an additional light source unit placed on an innerside of the side plate.

Appendix 24

The LED lighting apparatus as set forth in Appendix 23, furthercomprising an additional light-transmitting cover that covers theadditional light source unit.

Appendix 25

The LED lighting apparatus as set forth in Appendix 24, furthercomprising a reflective cover arranged inward of the light-transmittingcover and reflects light from the additional light source unit.

1F Embodiment

FIGS. 66-71 show an example of LED lighting apparatus according to avariation of the present invention. The LED lighting apparatus 101F ofthe present embodiment includes a support unit 200F, a plurality of LEDmodules 300, a power source unit 400, a receiver 500 and a cover 600.The LED lighting apparatus 101F is configured to be attached to e.g. apower supply portion 801 in a ceiling 800 via an attachment 802 for useas a ceiling light. It is to be noted that illustration of almostentirety of the cover 600 is omitted in FIG. 70 for easierunderstanding.

The support unit 200F constitutes the support structure of the LEDlighting apparatus 101F and includes a central member 210, a supportplate 220 and a pressing member 230, as shown in FIGS. 68-70. Thecentral member 210 is in the form of a ring having a generally U-shapedcross section and made as a one-piece member using a resin having apredetermined strength.

The support plate 220 is a member for supporting the LED modules 300 andmade by press-working a metal plate, for example. The support plate 220includes a connection portion 221F, an LED mount region 222F, and aperipheral portion 223F each of which is in the form of a ring. Theconnection portion 221F is a portion connected to the central member210. As shown in FIG. 69, the connection portion 221F overlaps the upperside, i.e., the ceiling 800 side, (installation side in the firstdirection of the present variation) of the central member 210 and isfixed to the upper end of the central member 210 by using e.g. a screw.As shown in FIGS. 69 and 70, the LED mount region 222F surrounds theconnection portion 221F as viewed in plan. The LED mount region 222F isa region where the LED modules 300 are mounted, and positioned on theupper side in FIG. 69 (installation side) with respect to the connectionportion 221F. The LED mount region 222F is in the form of a ring havingan outer diameter of about e.g. 250 mm. The LED mount region 222F has alower surface facing downward in the figure (toward the illuminationside in the first direction of the present variation) i.e., oppositeside of the ceiling 800. The lower surface extends along a planeperpendicular to the vertical direction in the figure.

As shown in FIG. 69, a height differentiating portion 224 is providedbetween the LED mount region 222F and the connection portion 221F. Theedge of the height differentiating portion 224 that is closer to the LEDmount region 222F is positioned on an upper side in the figure (theinstallation side) with respect to the edge of the heightdifferentiating portion 224 that is closer to the connection portion221F. The height differentiating portion 224 is inclined to be displacedtoward the upper side in the figure (installation side) as proceedingaway from the connection portion 221F outward within a planeperpendicular to the vertical direction.

The peripheral portion 223F surrounds the LED mount region 222F andpositioned on the lower side in the figure (illumination side) withrespect to the LED mount region 222F. A height differentiating portion225 is provided between the LED mount region 222F and the peripheralportion 223F. The height differentiating portion 225 is inclined to bedisplaced toward the lower side in the figure (illumination side) asproceeding away from LED mount region 222F outward within a planeperpendicular to the vertical direction. The height differentiatingportion 225 corresponds to an additional height differentiating portionin the present variation of the invention.

In the support plate 220, the respective lower surfaces of the heightdifferentiating portion 224, the LED mount region 222F, and the heightdifferentiating portion 225 (lower surfaces in FIG. 69) are paintedwhite and hence made highly reflective surfaces having high lightreflectance. The respective upper surfaces of the LED mount region 222F,the height differentiating portion 225 and the peripheral portion 223F(the ceiling 800-side surface of the support plate 220, i.e., uppersurfaces in FIG. 69) are made black or dark gray close to black bypainting, for example. A plurality of cushioning members 270 areprovided on the surface of the support plate 220 on the ceiling 800side.

The pressing member 230 is in the form of a ring having an L-shapedcross section and formed by e.g. press-working a metal plate. The outeredge of the pressing member 230 overlaps the connection portion 221F andfixed to the connection portion 221F by using e.g. a screw. The inneredge of the pressing member 230 overlaps the central member 210 andfixed to the lower end of the central member 210 by using e.g. a screw.

As will be understood from the above, the central member 210, theconnection portion 221F and the pressing member 230 form a hollowring-shaped portion having a rectangular cross section. The centralmember 210, the connection portion 221E′ and the pressing member 230provide an attachment region in the present variation of the invention.

The LED modules 300 are mounted to the lower surface of the LED mountregion 222F via a plurality of LED substrates 250. Each of the LEDsubstrates 250 is an insulating substrate made of e.g.glass-fiber-reinforced epoxy resin and in the form of a ring segment. Aplurality of LED modules 300 are mounted on each of the LED substrates250. In the present embodiment, four LED substrates 250 are arrangedadjacent to each other to form the shape of a ring as a whole.

Each of the LED modules 300 is in the form of an elongated rectangle asviewed in plan. FIG. 71 is a sectional view of the LED module 300 in aplane perpendicular to the width direction. As shown in the figure, theLED module 300 includes a pair of leads 320F, an LED chip 310F, asealing resin 340F and a case 330F. The paired leads 320F are made ofe.g. Cu alloy. The LED chip 310F is mounted on one of the leads 320F.The surfaces of the leads 320F opposite from the surface on which theLED chip 310F is mounted serve as mounting terminals 321F forsurface-mounting the LED module 300. The LED chip 310F is the lightsource of the LED module 300 and is configured to emit e.g. blue light.The sealing resin 340F protects the LED chip 310F. The sealing resin340F is made of a light-transmitting resin material containing afluorescent substance that emits yellow light when excited by light fromthe LED chip 310F. According to this structure, the LED module 300 canbe configured to emit light of a desired color temperature. Instead ofthe fluorescent substance that emits yellow light, mixture of afluorescent substance that emits red light and a fluorescent substancethat emits green light may be used. The case 330E′ is made of e.g. whiteresin and reflects the light traveling toward the sides from the LEDchip 310F in the upward direction. An LED of a type that uses two wiresfor connection to the paired leads 320F may be employed as the LED chip310F.

All the LED modules 300 may be the LED modules configured to emit lightof an incandescent color or those configured to emit light of a daylightwhite color. Alternatively, the LED modules 300 may comprise acombination of these two types of LED modules. In this embodiment, LEDmodules of an incandescent color and LED modules of a daylight whitecolor are employed. That is, the LED modules 300 consist of LED modules301 for emitting an incandescent color and LED modules 302 for emittinga daylight white color 302. For easier understanding, the incandescentcolor LED modules 301 are illustrated in black in FIG. 70.

In the present embodiment, the LED modules 300 are arranged on the LEDmount region 222F to form seven concentric circles as viewed in plan. Ineach of the circles of the LED modules 300, the incandescent color LEDmodules 301 and the daylight white color LED modules 302 are alternatelyarranged.

In this embodiment, as shown in FIG. 69, a support stay 260 is providedin the cover 600. The support stay 260 is arranged below the centralmember 210 in the figure. Below the support stay 260 is provided anannular LED substrate 261. A plurality of LED modules 300 are mounted ona circle on the LED substrate 261. All the LED modules 300 areincandescent color modules 301.

The power source unit 400 converts e.g. commercial AC of 100 V suppliedthrough a power supply portion 801 in the ceiling 800 to DC powersuitable for lighting the LED chips 310F and supplies the power to theLED modules 300. The power source unit 400 includes e.g. a transformer,a capacitor, a resistor, a diode and an IC. The power source unit 400 isconfigured to individually control the brightness of the incandescentcolor LED modules 301 and the brightness of the daylight white color LEDmodules 302. With this arrangement, the LED lighting apparatus 101F canemit light of a desired color from the incandescent color to thedaylight white color. The power source unit 400 can turn on or off theLED modules 300 supported on the support stay 260 (LED substrate 261)separately from other LED modules 300. In the present embodiment, asshown in FIG. 69, the power source unit 400 is accommodated in thehollow ring-shaped portion made up of the central member 210, theconnection portion 221F, and the pressing member 230.

The receiver 500 receives a signal transmitted from a transmittingportion, not shown, and is mounted on the LED substrate 261 in thepresent embodiment. The signal received by the receiver 500 is sent tothe power source unit 400. In accordance with the signal instruction,the power source unit 400 controls the lighting state of the LED modules300.

The cover 600 constitutes most of the appearance of the LED lightingapparatus 101F and includes a main illumination portion 610, an inclinedportion 620, an outer frame 630 and a center portion 640. The mainillumination portion 610 is made of e.g. milky-white translucent resin.Most part of the light from LED chips 310F (LED modules 300) passesthrough the main illumination portion 610 to be emitted to the outside.The main illumination portion 610 is in the form of a ring correspondingto the shape of the LED mount region 222F and covers the LED mountregion 222F. As shown in FIG. 69, the main illumination portion 610 isslightly inclined to be displaced downward in the figure as proceedingtoward the center.

The inclined portion 620 is connected to the outer periphery of the mainillumination portion 610 to surround the main illumination portion 610from outside. The inclined portion 620 is inclined to be displacedupward in the figure (installation side) as proceeding away from thecenter. As shown in FIGS. 66 and 69, the inclined portion 620 ispositioned on the outer side with respect to the LED mount region 222Fas viewed in plan (viewed in the first direction).

The outer frame 630 surrounds the inclined portion 620 from outside andis in the form of a ring. The outer frame 630 is made of e.g. atransparent resin or a milky white translucent resin. The outer frame630 is arranged to overlap the peripheral portion 223F of the supportplate 220 and fixed to the peripheral portion 223F. The center portion640 is made of e.g. a milky white translucent resin and arranged on theinner side of the main illumination portion 610. The center portion 640covers the support stay 260.

The advantages of the LED lighting apparatus 101F are described below.

According to the present embodiment, as described with reference to FIG.69, a height differentiating portion 224 is provided between the LEDmount region 222F and the connection portion 221F (attachment region).The edge of the height differentiating portion 224 that is closer to theLED mount region 222F is positioned on the upper side in the figure (theinstallation side) with respect to the edge of the heightdifferentiating portion 224 that is closer to the connection portion221F. Thus, the LED mount region 222F is retreated toward the ceiling800 side (installation side), so that the light path from the LED chips310F (LED modules 300) mounted on the LED mount region 222E′ to thecover 600 (main illumination portion 610) is made relatively long.Although the light emitted from the LED chips 310F (LED modules 300) hasa relatively high directivity, owing to the long light path to the cover600, unevenness of brightness is suppressed with respect to the lightemitted from the cover 600 to the outside. Thus, the LED lightingapparatus 101F can uniformly illuminate the room, while achievingenhanced appearance.

The height differentiating portions 224, 225 are inclined and the lowersurface of these height differentiating portions 224, 225 are madehighly reflective surfaces. Thus, light emitted from the LED chips 310F(LED modules 300) is efficiently directed toward the illumination side.The LED lighting apparatus 101F having this arrangement is suitable foruniform illumination with increased brightness.

The cover 600 includes the inclined portion 620 on the outer side of themain illumination portion 610, which is inclined to be displaced towardthe ceiling 800 side as proceeding outward. With the provision of thisinclined portion 620, the appearance of the LED lighting apparatus 101Fis enhanced. The outer frame 630 surrounding the inclined portion 620and the peripheral portion 223F of the support plate 220 overlapping theouter frame 630 provide a thin outer circumferential edge of the LEDlighting apparatus 101F. Generally, before attaching the LED lightingapparatus to the ceiling 800 or in the process of attaching or detachingthe LED lighting apparatus to the ceiling 800, the LED lightingapparatus 101F is held at the outer circumferential edge. Since theouter circumferential edge is thin, the LED lighting apparatus 101F iscarried easily with hands. Such thin outer circumferential edge alsoenhances the appearance.

The surfaces of the LED mount region 222F, the height differentiatingportion 225 and the peripheral portion 223F on the ceiling side(installation side) are made black or dark gray close to black(so-called contractive color). Thus, the LED lighting apparatus 101F hasgood appearance even when it is not attached to the ceiling 800.

The attachment region made up of the central member 210, the connectionportion 221F and the pressing member 230 support the weight of most partof LED lighting apparatus 101F including the support plate 220 and thecover 600, so that a large load is exerted on the attachment region. Inthe present embodiment, the central member 210, the connection portion221F and the pressing member 230 form a hollow ring-shaped portionhaving a rectangular cross section. The attachment region comprisingsuch a hollow ring-shaped portion having a rectangular cross section hasa relatively high mechanical strength, which is advantageous.

With the provision of the inclined height differentiating portion 224 inthe support plate 220, the strength is enhanced due to work hardening.

By the provision of incandescent color LED modules 301 and daylightwhite color LED modules 302, light of a desired color temperature fromthe incandescent color to the daylight color can be emitted from the LEDlighting apparatus 101F. The provision of the receiver 500 allowsadjustment of the color temperature and turn-on and off of the LEDlighting apparatus 101F to be performed properly from a distantposition. The space in the hollow ring-shaped portion made up of thecentral member 210, the connection portion 221F and the pressing member230 is efficiently used for accommodating the power source unit 400, sothat the LED lighting apparatus 101F has no useless space.

FIGS. 72-76 show other embodiments of this variation of the presentinvention. In these figures, the elements that are identical or similarto those of the foregoing embodiments are designated by the samereference signs as those used for the foregoing embodiment.

2F Embodiment

FIGS. 72-74 show an LED lighting apparatus 102F according to 2Fembodiment of the variation of the present invention. The LED lightingapparatus 102F of the present embodiment mainly differs from theforegoing embodiment in structure of the LED mount region 222F.

In the present embodiment, as shown in FIGS. 72 and 73, the LED mountregion 222F has a plurality of mountain portions 222 a on its lower sidein the figure (illumination side). Each of the mountain portions 222 aincludes two surfaces 222 b and 222 c (second surface and third surface)which are inclined with respect to a surface 220 a (first surface)perpendicular to the vertical direction. As shown in FIG. 73, thesurface 222 b and the surface 222 c adjoin with each other in thecircumferential direction of the LED mount region 2221. As shown in FIG.74, the inclination angle α of the surface 222 b with respect to thesurface 220 a is smaller than the inclination angle β of the surface 222c with respect to the surface 220 a. Thus, the surface 222 b has arelatively gentle inclination. The inclination angle α of the surface222 b is in the range of e.g. 5° to 20°.

In the present embodiment, as shown in FIG. 73, the mountain portions222 a are aligned in the circumferential direction of the LED mountregion 222F to form four concentric circles as viewed in plan. Themountain portions 222 a are made by e.g. press working.

In the present embodiment, the LED modules 300 are mounted on the LEDmount region 222F via a flexible substrate 290. Specifically, theflexible substrate 290 comprises a resin layer and a metal layerproviding a wiring pattern (not shown), and is in the form of a ring tocover the surfaces 222 b, 222 c of the mountain portions 222 a alignedin the circumferential direction of the LED mount region 2221. The LEDmodules 300 are mounted on the flexible substrate 290. The LED modules300 are mounted on the surfaces 222 b. On each of the surfaces 222 b, anincandescent color LED module 301 and a daylight white color LED module302 are mounted as aligned in the circumferential direction of the LEDmount region 222F. Thus, on the flexible substrate 290, the incandescentcolor LED modules 301 and the daylight white color LED modules 302 arealternately arranged in the circumferential direction of the LED mountregion 222F. As the flexible substrate 290, a plate with white resist toprovide a high reflectance may be suitably used.

In the LED lighting apparatus 1021 according to the present embodiment,a height differentiating portion 224 is provided between the LED mountregion 222F and the connection portion 221F (attachment region). Owingto the height differentiating portion 224, the LED mount region 222F isretreated toward the ceiling 800 side (installation side) opposite fromthe illumination side. Thus, the light path from the LED chips 310F (LEDmodules 300) mounted on the LED mount region 222F to the cover 600 (mainillumination portion 610) is made relatively long. Owing to the longlight path, unevenness of brightness is suppressed with respect to thelight emitted from the cover 600 to the outside. Thus, the LED lightingapparatus 102F can uniformly illuminate the room, while achievingenhanced appearance.

The LED modules 300 are mounted on the surfaces 222 b inclined withrespect to the surface 220 a perpendicular to the vertical direction(see FIG. 74). This arrangement makes the light path from the LEDmodules 300 to the cover 600 longer. This arrangement is suitable forachieving uniform illumination with reduced unevenness in brightness.The surface 222 b on which the LED modules 300 are mounted are gentlyinclined, and a plurality of LED modules 300 (two in the presentembodiment) are mounted on each of the surfaces 222 b. This structureallows efficient placing of the LED modules 300 on the surfaces 222.Further, the surfaces 222 b and 222 c, which make each mountain portion222 a, adjoin each other in the circumferential direction of the LEDmount region 222F, and the plurality of such mountain portions 222 a arearranged in the circumferential direction. With this structure, the LEDmodules 300 are properly mounted on the surfaces 222 b by using thering-shaped flexible substrate 290. Since the flexible substrate 290 ismade white, light from the LED chips 310F (LED modules 300) is reflectedby the flexible substrate 290, whereby the brightness of the light fromthe LED lighting apparatus 102F is expected to increase.

On each of the surfaces 222 b are mounted an incandescent color LEDmodule 301 and a daylight white color LED module 302, and theincandescent color LED module 301 and the daylight white color LEDmodule 302 forming one pair are arranged close to each other. Forinstance, when lighting of only the incandescent color is demanded, allthe daylight white color LED modules 302 are turned off. Since theincandescent color LED module 301 and the daylight white color LEDmodule 302 in each pair are close to each other, the density of the LEDmodules 300 as the light-emitting points does not differ largely betweenwhen only the incandescent color LED modules 301 are turned on and whenall the LED modules 300 are turned on. Thus, according to thisarrangement, brightness variations caused by color temperatureadjustment is suppressed.

3F Embodiment

FIGS. 75 and 76 show an LED lighting apparatus 103F according to 3Fembodiment of the variation of the present invention. The LED lightingapparatus 103F of the present embodiment mainly differs from theforegoing embodiment in structure of the LED mount region 222F.

In the present embodiment, a height differentiating portion is notprovided between the connection portion 221F and the LED mount region222F, and the LED mount region 222F is connected to the outer peripheryof the connection portion 221F in flush with the connecting portion.

In the present embodiment, the LED mount region 222F has a plurality ofmountain portions 222 d on its upper side in the figure (installationside). Each of the mountain portions 222 d includes two surfaces 222 eand 222 f which are inclined with respect to a surface 220 aperpendicular to the vertical direction. In this embodiment, theprojecting direction of the mountain portions 222 d is opposite fromthat of the mountain portions 222 a of the above-described LED lightingapparatus 102F. The surface 222 e and the surface 222 f are inclinedsurfaces corresponding to the surface 222 b and the surface 222 c,respectively, of the LED lighting apparatus 102F. Though notillustrated, the surface 222 e and the surface 222 f adjoin with eachother in the circumferential direction of LED mount region 222F. Asshown in FIG. 76, the inclination angle α of the surface 222 e withrespect to the surface 220 a is smaller than the inclination angle β ofthe surface 222 f with respect to the surface 220 a. Thus, the surface222 e has a relatively gentle inclination. The mountain portions 222 dare aligned in the circumferential direction of the LED mount region222E to form four concentric circles. The LED modules 300 are mounted onthe surfaces 222 e via a flexible substrate 290.

In the LED lighting apparatus 103F, the LED modules 300 are mounted onthe surfaces 222 e inclined with respect to the surface 220 aperpendicular to the vertical direction (see FIG. 76). This arrangementmakes the light path from the LED modules 300 to the cover 600 longer.This arrangement is suitable for achieving uniform illumination withreduced unevenness in brightness.

The surface 222 f, which is adjacent to the surface 222 e on which theLED modules 300 are mounted, has an inclination angle β that is largerthan the inclination angle α of the surface 222 e. Thus, the surface 222f (more specifically, the flexible substrate 290 on the surface 222 f)serves as a reflective surface. The LED lighting apparatus 103F havingthis structure is suitable for achieving uniform illumination withincreased brightness. The LED lighting apparatus according to thevariation of the invention is not limited to the foregoing embodiment.The specific structure of each part of the LED lighting apparatusaccording to the variation of the invention may be varied in design inmany ways.

The feature of the present variation of the invention is described belowas Appendixes.

Appendix 1

An LED lighting apparatus comprising:

-   -   a support unit including an LED mount region in the form of a        ring facing an illumination side which is one side in a first        direction, and an attachment region to be attached to a power        supply portion, the attachment region being surrounded by the        LED mount region in a second direction and a third direction        which are perpendicular to the first direction and perpendicular        to each other;    -   a plurality of LED chips mounted on the LED mount region; and    -   a cover that is arranged on the illumination side in the first        direction with respect to the LED mount region and transmits        light from the LED chips,    -   wherein a height differentiating portion is provided between the        LED mount region and the attachment region, an edge of the        height differentiating portion that is closer to the LED mount        region is displaced toward an installation side, which is the        other side in the first direction, from an edge of the height        differentiating portion that is closer to the attachment region.

Appendix 2

The LED lighting apparatus as set forth in Appendix 1, wherein theheight differentiating portion is inclined to be displaced toward theinstallation side in the first direction as proceeding away from theattachment region in the second and the third directions.

Appendix 3

The LED lighting apparatus as set forth in Appendix 1 or 2, wherein asurface of the height differentiating portion on the illumination sidein the first direction comprises a light reflective surface having ahigh light reflectance.

Appendix 4

The LED lighting apparatus as set forth in any one of Appendixes 1-3,wherein the support unit further includes a peripheral portion in theform of a ring surrounding the LED mount region in the second and thethird directions and positioned on the illumination side in the firstdirection with respect to the LED mount region, and an additional heightdifferentiating portion positioned between the peripheral portion andthe LED mount region.

Appendix 5

The LED lighting apparatus as set forth in Appendix 4, wherein theadditional height differentiating portion is inclined to be displacedtoward the illumination side in the first direction as proceeding awayfrom a center in the second and the third directions.

Appendix 6

The LED lighting apparatus as set forth in Appendix 4 or 5, whereinsurfaces of the LED mount region and the additional heightdifferentiating portion on the installation side in the first directionare made black or dark gray close to black.

Appendix 7

The LED lighting apparatus as set forth in any one of Appendixes 4-6,wherein the cover includes an outer frame in the form of a ringoverlapping the peripheral portion of the support unit as viewed in thefirst direction, and an inclined portion surrounded by the outer frameand inclined to be displaced toward the installation side in the firstdirection as proceeding away from a center in the second and the thirddirections.

Appendix 8

The LED lighting apparatus as set forth in Appendix 7, wherein theinclined portion is positioned on an outer side with respect to the LEDmount region as viewed in the first direction.

Appendix 9

The LED lighting apparatus as set forth in any one of Appendixes 1-8,wherein the attachment region includes a hollow ring-shaped portionhaving a rectangular cross section.

Appendix 10

The LED lighting apparatus as set forth in any one of Appendixes 1-9,wherein: the LED mount region includes a second surface inclined withrespect to a first surface extending along the first direction and thesecond direction, and

-   -   the LED chips are mounted on the second surface.

Appendix 11

The LED lighting apparatus as set forth in Appendix 10, wherein the LEDmount region is provided with a plurality of mountain portions each ofwhich includes the second surface and a third surface adjoining thesecond surface and projects toward one of the illumination side and theinstallation side in the first direction.

Appendix 12

The LED lighting apparatus as set forth in Appendix 11, wherein all ofthe mountain portions project toward the illumination side in the firstdirection.

Appendix 13

The LED lighting apparatus as set forth in Appendix 11 or 12, whereinthe third surface is inclined with respect to the first surface at aninclination angle larger than an inclination angle of the second surfacewith respect to the first surface.

Appendix 14

The LED lighting apparatus as set forth in any one of Appendixes 11-13,wherein the LED mount region is in the form of a ring as viewed in thefirst direction.

Appendix 15

The LED lighting apparatus as set forth in Appendix 14, wherein thesecond surface and the third surface adjoin with each other in acircumferential direction of the LED mount region.

Appendix 16

The LED lighting apparatus as set forth in Appendix 14 or 15, wherein atleast two of the LED chips are mounted on each of the second surfaces.

Appendix 17

The LED lighting apparatus as set forth in any one of Appendixes 14-16,further comprising a plurality of LED modules each including the LEDchip and a sealing resin covering the LED chip, the sealing resincontaining a fluorescent substance for emitting light of a wavelengthdifferent from a wavelength of light from the LED chip.

Appendix 18

The LED lighting apparatus as set forth in Appendix 17, wherein theplurality of LED modules include a first LED module and a second LEDmodule which differ from each other in color temperature of light to beemitted.

Appendix 19

The LED lighting apparatus as set forth in Appendix 18, wherein thefirst LED module emits light of an incandescent color, whereas thesecond LED module emits light of a daylight white color.

Appendix 20

The LED lighting apparatus as set forth in Appendix 18 or 19, whereinsaid at least two LED modules mounted on the second surface includes thefirst LED module and the second LED module, the first LED module and thesecond LED module being alternately arranged in a circumferentialdirection of the LED mount region.

Appendix 21

The LED lighting apparatus as set forth in any one of Appendixes 10-20,wherein the second surface is inclined with respect to the first surfaceat an inclination angle in a range of 5°-20°.

1G Embodiment

FIGS. 78-85 show an example of LED lighting apparatus according to avariation of the present invention. The LED lighting apparatus 101G ofthe present embodiment includes a support unit 200G, a plurality of LEDmodules 300, a power source unit 400, a receiver 500 and a cover 600.The LED lighting apparatus 101G is configured to be attached to e.g. apower supply portion 801 in a ceiling 800 via an attachment 802 for useas a ceiling light. It is to be noted that illustration of almostentirety of the cover 600 is omitted in FIG. 82 for easierunderstanding.

The support unit 200G constitutes the support structure of the LEDlighting apparatus 101 and includes a central member 210, a supportplate 220 and an inner partition member 230G and an outer partitionmember 240G, as shown in FIGS. 80-82. The central member 210 is in theform of a ring having a generally U-shaped cross section and made as aone-piece member using a resin having a predetermined strength.

The support plate 220 is a member for supporting the LED modules 300 andmade by press-working a metal plate, for example. The support plate 220includes a connection portion 221G, an LED mount region 222G, and aperipheral portion 223G each of which is in the form of a ring. Theconnection portion 221G is a portion connected to the central member210. As shown in FIG. 81, the connection portion 221G overlaps the upperside, i.e., the ceiling 800 side (installation side in the firstdirection of the present variation) of the central member 210 and isfixed to the upper end of the central member 210 by using e.g. a screw.As shown in FIGS. 81 and 82, the LED mount region 222G surrounds theconnection portion 221G as viewed in plan. The LED mount region 222G isa region where the LED modules 300 are mounted, and positioned on theupper side in FIG. 81 (installation side) with respect to the connectionportion 221G. The LED mount region 222G has a support surface 222 dfacing downward in the figure (toward the illumination side in the firstdirection of the present variation) i.e., opposite side of the ceiling800. The support surface 222 d extends along a plane perpendicular tothe vertical direction in the figure. As shown in FIG. 81, a heightdifferentiating portion 224 is provided between the LED mount region222G and the connection portion 221G.

The peripheral portion 223G surrounds the LED mount region 222G andpositioned on the lower side in the figure (illumination side) withrespect to the LED mount region 222G. A height differentiating portion225 is provided between the LED mount region 222G and the peripheralportion 223G.

In the support plate 220, the respective lower surfaces of the heightdifferentiating portion 224, the LED mount region 222G, and the heightdifferentiating portion 225 (lower surfaces in FIG. 81) are paintedwhite and hence made highly reflective surfaces having high lightreflectance. A plurality of cushioning members 270 are provided on thesurface of the support plate 220 on the ceiling 800 side.

A plurality of LED substrates 250 are supported on the support surface222 d of the LED mount region 222G, and a plurality of LED modules 300are mounted on each of the LED substrates 250. The LED substrate 250 isan insulating substrate made of e.g. glass-fiber-reinforced epoxy resinand in the form of a ring segment. As shown in FIG. 82, in the presentembodiment, six LED substrates 250 are arranged adjacent to each otherto form the shape of a ring as a whole.

Each LED substrate 250 has connector 251, 252, 253, 254 at an innerportion in the radial direction. The connectors 251-254 form a pluralityof pairs at adjacent edges of adjacent LED substrates 250. Connectors251, 252 are provided on one of two adjacent LED substrates 250, whereasconnectors 253, 254 are provided on the other one of the two adjacentLED substrates 250. In this embodiment, the connectors 251 and 254 forma pair (first pair), and the connectors 252 and 253 form another pair(second pair). Each of the connectors 252 and 253 is positioned on theouter side of the pair of connectors 251, 254 in the circumferentialdirection of the LED substrate 250.

As shown in FIGS. 82 and 83, connection ends 255 a, 256 a of wirings255, 256 are connected to the connectors 251-254 along a plane of theLED substrate 250. In this embodiment, the connection ends 255 a, 256 aof the wirings 255, 256 are male terminals, which are inserted intocylindrical female terminals of the connectors 251-254. For instance,the connection ends 255 a, 256 a are in the form of a round rod andinserted into the connectors 251-254 while sandwiching the conductionportions of the wirings 255, 256. With this arrangement, in connectingthe connection ends 255 a, 256 a to the connectors 251-254, theconnection ends 255 a, 256 a (wirings 255, 256) are in a rotatable staterelative to the connectors 251-254. By connecting opposite connectionends 255 a of the wiring 255 to the paired connectors 251 and 254,adjacent LED substrates 250 are electrically connected to each other viathe wiring 255. Similarly, by connecting opposite connection ends 256 aof the wiring 256 to the paired connectors 252 and 253, adjacent LEDsubstrates 250 are electrically connected to each other via the wiring256. As noted before, the connectors 252 and 253 are arranged on theouter side of the connectors 251 and 254 in the circumferentialdirection n1 of the LED substrates 250. Correspondingly to thearrangement of the connectors 251-254, the wiring 256 for connection tothe connectors 252, 253 is made longer than the wiring 255 forconnection to the connectors 251, 254, and there is a considerabledifference in length between the wires 255 and 256. In FIG. 82, thewirings 255, 256 are illustrated as connected to only some of aplurality of pairs of adjacent LED substrates 250, and illustration ofthe wirings is omitted with respect to remaining pairs of LED substrates250.

As better shown in FIG. 83, the connection ends 255 a, 256 a areconnected to the connectors 251-254 in directions d1-d4 crossing thecircumferential direction n1 of the LED substrates 250. In thisembodiment, the connection directions d1-d4 are along the radialdirection of the LED substrates 250 and oriented from the inner sidetoward the outer side in the radial direction.

In this embodiment, the LED substrates 250 have cutouts 257 at theedges. Each cutout 257 is positioned at an inner end in the radialdirection and at an edge in the circumferential direction of each LEDsubstrate 250. The support surface 222 d of the support plate 220 isformed with a positioning portion 226. The positioning portion 226 isformed by e.g. silkscreen printing and has a color slightly darker thanthe white painting of the support surface 222 d. The positioning portion226 is provided at a position that corresponds to the cutout 257 whenthe LED substrate 250 is placed on the support surface 222 d. The cutout257 and the positioning portion 226 provide the positioner in thisvariation of the invention.

As shown in FIG. 81, each of the inner and the outer partition members230G, 240G is in the form of a ring having a generally L-shaped crosssection and made by e.g. press-working a metal plate. The inner and theouter partition members 230G and 240G include partition walls 231G and241G, respectively, extending in the vertical direction in the figure.The partition walls 231G and 241G are spaced from each other in theradial direction of the LED substrates 250.

As shown in FIGS. 81 and 84, each of the partition walls 231G and 241Gis formed with a plurality of through-holes 232G and 242G penetrating inthe radial direction of the LED substrates 250. As shown in FIG. 84, thethrough-holes 232G in the partition wall 231G are arranged in two upperand lower rows extending in the circumferential direction of the LEDsubstrates 250. That is, the through-holes 232G include a plurality ofthrough-holes 232 a positioned on the lower side in the figure(illumination side) and a plurality of through-holes 232 b positioned onthe upper side in the figure (installation side). The through-holes 242Gin the partition wall 241G are arranged in two upper and lower rowsextending in the circumferential direction of the LED substrates 250.That is, the through-holes 242G include a plurality of through-holes 242a positioned on the lower side in the figure (illumination side) and aplurality of through-holes 242 b positioned on the upper side in thefigure (installation side). The through-holes 2326 (232 a, 232 b) formedin the partition wall 2316 and the through-holes 2426 (242 a, 242 b)formed in the partition wall 241G do not overlap each other in theradial direction of the LED substrates 250. The through-holes 2326 and2426 account for 30% or less of the area of the partition walls 2316 and2416, respectively. With this proportion, reduction in strength of thepartition walls 2306, 2406 is prevented.

The upper ends of the inner and the outer partition members 2306, 2406overlap the connection portion 2216 and are fixed to the connectionportion 2216 by using e.g. a screw. The lower end of the inner partitionmember 230G is fixed to the lower end of the outer partition member240G. The lower end of the outer partition member 240G overlaps thecentral member 210 and is fixed to the central member 210 by using e.g.a screw.

As will be understood from FIG. 81, the central member 210, theconnection portion 2216 and the partition members 230G, 2406 form ahollow ring-shaped portion having a rectangular cross section. As willbe described later, the power source unit 400 and an adsorbent 700 areplaced in the hollow ring-shaped portion. The LED accommodating space201 (LED accommodating portion) in which the LED substrates 250 areaccommodated and the power source accommodating space 202 (power sourceaccommodating portion) in which the power source unit 400 isaccommodated are partitioned by the partition walls 231G, 241G. However,the LED accommodating space 201 and the power source accommodating space202 communicate with each other via the through-holes 232G, 242G formedin the partition walls 231G, 241G.

Each of the LED modules 300 is in the form of an elongated rectangle asviewed in plan. FIG. 85 is a sectional view of the LED module 300 in aplane perpendicular to the width direction. As shown in the figure, theLED module 300 includes a pair of leads 320G, an LED chip 310G, asealing resin 340G and a case 330G. The paired leads 320G are made ofe.g. Cu alloy. The LED chip 310G is mounted on one of the leads 320G.The surfaces of the leads 320G opposite from the surface on which theLED chip 310G is mounted serve as mounting terminals 321G forsurface-mounting the LED module 300. The LED chip 310G is the lightsource of the LED module 300 and is configured to emit e.g. blue light.The sealing resin 340G protects the LED chip 310G. The sealing resin340G is made of a light-transmitting resin material containing afluorescent substance that emits yellow light when excited by light fromthe LED chip 310G. According to this structure, the LED module 300 canbe configured to emit light of a desired color temperature. Instead ofthe fluorescent substance that emits yellow light, mixture of afluorescent substance that emits red light and a fluorescent substancethat emits green light may be used. The case 330G is made of e.g. whiteresin and reflects the light traveling toward the sides from the LEDchip 310G in the upward direction. An LED of a type that uses two wiresfor connection to the paired leads 320G may be employed as the LED chip310G.

All the LED modules 300 may be the LED modules configured to emit lightof an incandescent color or those configured to emit light of a daylightwhite color. Alternatively, the LED modules 300 may comprise acombination of these two types of LED modules. In this embodiment, LEDmodules of an incandescent color and LED modules of a daylight whitecolor are employed. That is, the LED modules 300 consist of LED modules301 for emitting an incandescent color and LED modules 302 for emittinga daylight white color 302. For easier understanding, the incandescentcolor LED modules 301 are illustrated in black in FIG. 82.

In the present embodiment, the LED modules 300 are arranged on the LEDmount region 222G to form seven concentric circles as viewed in plan. Ineach of the circles of the LED modules 300, the incandescent color LEDmodules 301 and the daylight white color LED modules 302 are alternatelyarranged.

In this embodiment, as shown in FIG. 81, a support stay 260 is providedin the cover 600. The support stay 260 is arranged below the centralmember 210 in the figure. Below the support stay 260 is provided acircular substrate 261. A plurality of LED modules 300 are mounted on acircle on the substrate 261. All the LED modules 300 are incandescentcolor modules 301.

The power source unit 400 converts e.g. commercial AC of 100 V suppliedthrough a power supply portion 801 in the ceiling 800 to DC powersuitable for lighting the LED chips 310F and supplies the power to theLED modules 300. The power source unit 400 includes e.g. a transformer,a capacitor, a resistor, a diode and an IC. The power source unit 400 isconfigured to individually control the brightness of the incandescentcolor LED modules 301 and the brightness of the daylight white color LEDmodules 302. With this arrangement, the LED lighting apparatus 101G canemit light of a desired color from the incandescent color to thedaylight white color. The power source unit 400 can turn on or off theLED modules 300 supported on the support stay 260 (substrate 261)separately from other LED modules 300. In the present embodiment, asshown in FIG. 81, the power source unit 400 is accommodated in the powersource accommodating space 202 in the hollow ring-shaped portion made upof the central member 210, the connection portion 221G, and thepartition members 230G, 240G.

The receiver 500 receives a signal transmitted from a transmittingportion, not shown, and is mounted on the substrate 261 in the presentembodiment. The signal received by the receiver 500 is sent to the powersource unit 400. In accordance with the signal instruction, the powersource unit 400 controls the lighting state of the LED modules 300.

The cover 600 constitutes most of the appearance of the LED lightingapparatus 101 and includes a main illumination portion 610, an outerframe 620 and a center portion 640. The main illumination portion 610 ismade of e.g. milky-white translucent resin. Most part of the light fromLED chips 310G (LED modules 300) passes through the main illuminationportion 610 to be emitted to the outside. The main illumination portion610 is in the form of a ring corresponding to the shape of the LED mountregion 222G and covers the LED mount region 222G. As shown in FIG. 81,the main illumination portion 610 is slightly inclined to be displaceddownward in the figure as proceeding toward the center.

The outer frame 620 surrounds main illumination portion 610 from outsideand is in the form of a ring. The outer frame 620 is made of e.g. atransparent resin or a milky white translucent resin. The outer frame620 is arranged to overlap the peripheral portion 223G of the supportplate 220 and fixed to the peripheral portion 223G. The outer diameterof the outer frame 620 (cover 600) is e.g. about 600 mm. The centerportion 640 is made of e.g. a milky white translucent resin and arrangedon the inner side of the main illumination portion 610. The centerportion 640 covers the support stay 260.

As shown in FIG. 81, the adsorbent 700 in the power source accommodatingspace 202 is filled in a hollow container 710 having vent holes (notshown). As the adsorbent 700, a porous material that adsorbs brominecompound well is suitably used. Examples of such material includezeolite and charcoal powder. The adsorbent 700 may contain either orboth of zeolite and charcoal powder.

The advantages of the LED lighting apparatus 101G are described below.

According to this embodiment, as described with reference to FIG. 83,the connection directions d1, d4 and d2, d3 in which the connection ends255 a, 256 a of the wirings 255, 256 are connected to the connectors251, 254 and the connector 252, 253 are along the radial direction ofthe LED substrates 250. With this arrangement, the female terminals(connection portions) of the connectors 251, 254 and the connectors 252,253 are arranged side by side so as not to face each other. Thus, evenwhen rotation moment is exerted between the connectors 251, 254 and thewiring 255 or between the connectors 252, 253 and the wiring 256, thewirings 255, 256 are prevented from unduly rotating. Thus, such asituation that light from the LED chips 310G (LED modules 300) isblocked due to unintentional movement of the curved portions of thewirings 255, 256 is avoided. Thus, the LED lighting apparatus 101Gachieves more uniform illumination.

With the arrangement in which the connection directions d1, d4 and d2,d3 are along the radial direction of the LED substrates 250, theconnection directions d1 and d4 are generally parallel to each other, soare the connection directions d2 and d3. This arrangement is suitablefor reliably preventing rotation of the wires 255, 256 and henceachieving uniform illumination. Moreover, the generally parallelconnection directions d1, d4 as well as the generally parallelconnection directions d2, d3 facilitate the work of connecting thewirings 255, 256 (connection ends 255 a, 256 a) to the connectors251-254.

In this embodiment, for adjacent ones of the LED substrates 250, aplurality of pairs of connectors 251, 254 and 252, 253 are provided.With this structure, when the LED modules 300 include a plurality oftypes of LED modules that emit light of different color temperatures,such as incandescent color LED modules 301 and daylight color LEDmodules 302, a plurality of pairs of connectors 251, 254 and 252, 253are allotted to each type of the LED modules. This is favorable forindividually controlling different types of LED modules 300.

Each of the connectors 252, 253 is arranged on the outer side withrespect to the pair of the connectors 251, 254 in the circumferentialdirection of the LED substrates 250. Correspondingly to this arrangementof the connectors 251-254, the wiring 255 for connection to the innerconnectors 251, 254 and the wiring 256 for connection to the outerconnectors 252, 253 are made to have a considerable difference inlength. Thus, connection of the wirings 255, 256 to wrong connectors251-254 is prevented, so that improper connection of the wrings 255, 256is reliably prevented.

In placing the LED substrates 250 on the support plate 220, the LEDsubstrates 250 can be arranged at proper positions by positioning thecutouts 257 of the LED substrates 250 relative to the positioningportions 226 of the support plate 220. Thus, the LED substrates 250 arearranged at equal intervals. Accordingly, the wirings 255, 256 forconnection to the connectors 251, 254 and the connectors 252, 253 do notneed to be made insufficiently long to compensate for intervalvariations.

The partition walls 231G and 241G, which partition between the LEDaccommodating space 201 accommodating the LED substrates 250 and thepower source accommodating space 202 accommodating the power source unit400, have a plurality of through-holes 232G and a plurality ofthrough-holes 242G, respectively. Generally, the volume of the powersource accommodating space 202 is considerably small as compared withthat of the LED accommodating space 201, and the power sourceaccommodating space 202 tends to be heated up due to the heat generatedby the power source unit 400. According to the LED lighting apparatus101G, however, air in the power source accommodating space 202 flowsinto the LED accommodating space 201 through the through-holes 232G and242G, so that the power source accommodating space 202 is prevented frombeing heated up.

Due to the heat of the power source unit 400, bromine in flux, which isused for the parts or the assembling of the power source unit 400, maybe diffused into the power source accommodating space 202 and exists asa bromine compound. A bromine compound can be a cause for thedeterioration of the LED modules 300, and the bromine compound in thepower source accommodating space 202 may enter the LED accommodatingspace 201 via the through-holes 232G, 242G. In this embodiment, however,the adsorbent 700 is arranged in the power source accommodating space202. Thus, by adsorbing the bromine compound by the adsorbent 700, thebromine compound is prevented from entering the LED accommodating space201 side, whereby deterioration of the LED modules 300 is prevented.

The through-holes 232G and 242G formed in the partition walls 231G and241G include through-holes 232 a, 232 b and through-holes 242 a, 242 b,respectively, arranged in two upper and lower rows. According to thisarrangement, when the temperature of the power source accommodatingspace 202 becomes higher than that of the LED accommodating space 201,air of a higher temperature in the power source accommodating space 202flows into the LED accommodating space 201 through the through-holes 232b and 242 b in the upper rows, while air of a lower temperature in theLED accommodating space 201 flows into the power source accommodatingspace 202 through the through-holes 232 a and 242 a in the lower rows.Thus, air convection easily occurs between the LED accommodating space201 and the power source accommodating space 202. This is favorable forpreventing the power source accommodating space 202 from beingexcessively heated.

The through-holes 232G (232 a, 232 b) in the partition wall 231G and thethrough-holes 242G (242 a, 242 b) in the partition wall 241G do notoverlap each other as viewed in the radial direction of the LEDsubstrates 250. According to this arrangement, even when the lighttraveling within the LED accommodating space 201 inward in the radialdirection of the substrates 250 passes through the through-holes 242G ofthe partition wall 241G positioned on the outer side in the radialdirection, the light is reflected by the surface of the partition wall231G on the inner side to return into the LED accommodating space 201through the through-holes 242G. Thus, the light traveling within the LEDaccommodating space 201 is prevented from traveling into the powersource accommodating space 202, which contributes to the uniformillumination by the LED lighting apparatus 101G.

The portion made up of the central member 210, the connection portion221G and the partition members 230G, 240G support the weight of mostpart of LED lighting apparatus 101G including the support plate 220 andthe cover 600, so that a large load is exerted on this portion. In thepresent embodiment, the central member 210, the connection portion 221Gand the partition members 230G, 240G form a hollow ring-shaped portionhaving a rectangular cross section. The provision of such a hollowring-shaped portion enhances the mechanical strength.

As shown in FIGS. 81 and 82, on the inner side of the center portion 640of the cover 600, the substrate 261 in the form of a ring is arranged onthe inner side of the LED substrates 250 in the radial direction, and aplurality of LED modules 300 are mounted on the substrate 261 to form acircle. In this LED lighting apparatus 101G, the LED modules 300 on thesubstrate 261 can be configured to be turned on separately from otherLED modules, to function as a circular night light.

FIG. 86 shows another embodiment of this variation of the presentinvention. In these figures, the elements that are identical or similarto those of the foregoing embodiment are designated by the samereference signs as those used for the foregoing embodiment.

In the LED lighting apparatus 101G of the foregoing embodiment, a lightemitting portion in the form of a ring (LED modules 300 on the substrate261) is provided on the inner side of the center portion 640 of thecover 600. Unlike this, in the LED lighting apparatus 102G of thisembodiment shown in FIG. 86, a light emitting portion in the form of aring is arranged near the outer frame 620 of the cover 600. In FIG. 86,only the portions of the LED lighting apparatus 102G which need to beillustrated for describing the difference from the foregoing embodimentare shown, and illustration of other portions is omitted.

The LED lighting apparatus 102G of this embodiment includes a lightguide 280 and a reflector 281 that covers part of the light guide 28.The light guide 280 is made of e.g. transparent acrylic resin andgenerally in the form of a ring-shaped plate. The light guide 280 servesto guide the light from the LED modules 300 provided adjacent to theouter periphery of the LED substrates 250 outward in the radialdirection of the cover 60. The light guide 280 includes an incidentsurface 280 a facing the LED modules 300 and emission surfaces 280 b,280 c. The reflector 281 in made of e.g. white resin. The portion of thelight guide 280 from the inner side to the center in the radialdirection is sandwiched between the reflector 281 and the peripheralportion 223G of the support plate 220. The outer end in the radialdirection of the light guide 280 is exposed from the reflector 281 andthe peripheral portion 223G. Of the exposed portion, the surface facingupward in the figure (ceiling 800 side) provides the emission surface280 b, whereas the surface facing downward in the figure provides theemission surface 280 c. The emission surfaces 280 b, 280 c are roughsurfaces with minute irregularities.

Light emitted from the LED modules 300 facing the incident surface 280 aof the light guide 280 enters the light guide 280 through the incidentsurface 280 a and travels outward in the radial direction while beingrepetitively reflected within the light guide 280. The radially innerregion of the light guide 280 is sandwiched between the reflector 281and the peripheral portion 223G, so that the light within the lightguide 280 does not easily travel to the outside. The light traveling inthe light guide 280 in the radial direction is emitted to the outsidethrough the emission surfaces 280 b, 280 c. The LED modules 300 facingthe incident surface 280 a are configured to be turned on or ofseparately from other LED modules 300 on the LED substrates 250.

In the LED lighting apparatus 102G of this embodiment, only the LEDmodules 300 facing the incident surface 280 a can be turned on to emitlight from the emission surfaces 280 b and 280 c, which are positionedon the outer periphery of the LED lighting apparatus 102G, toward theceiling 800 side and the opposite side, to function as a circular nightlight.

The LED lighting apparatus according to the variation of the inventionis not limited to the foregoing embodiment. The specific structure ofeach part of the LED lighting apparatus according to the variation ofthe invention may be varied in design in many ways.

In the above-described embodiment, the connection directions (first andsecond connection directions) of the connection ends of the wirings tothe connectors (first connector and second connector) making one pairwith respect to two adjacent LED substrates are along the radialdirection of the LED substrates. However, the invention is not limitedto this arrangement, and the first and the second connection directionsmay cross the radial direction of the LED substrates. In this case, thefirst and the second connectors may be arranged such that the first andthe second connection directions be parallel to each other or graduallyseparate from each other as proceeding from the inner side toward theouter side (forward in the connection directions) in the radialdirection. With this arrangement again, undesirable rotation of thewirings connected to the first and the second connectors is prevented.FIG. 87 shows the example in which the first and the second connectiondirections gradually separate from each other as proceeding forward inthe connection directions. In this figure, only the elementscorresponding to the connectors 251, 254, the wiring 255 and theadjacent elements shown in FIG. 83 are illustrated as designated by thesame reference signs as those used in FIG. 83. As shown in FIG. 87, itis preferable that the connection direction d1 of the connection end 255a to the connector 251 and the connection direction d4 of the connectionend 255 a to the connector 254 form an angle α of 90° or less. When theangle α is 90°, the rotation direction of the wiring 255 relative to theconnector 251 and the rotation direction of the wiring 255 relative tothe connector 254 form a right angle, so that rotation of the wiring 255relative to the connectors 251, 254 is properly prevented. As will beunderstood from this, when the angle α formed by the connectiondirections d1 and d4 is smaller than 90°, rotation of the wiring 255 isless likely to occur than when the angle α is 90°, so that rotation ofthe wiring 255 relative to the connectors 251, 254 is properlyprevented.

Although the first and the second connectors are arranged on the innerportion in the radial direction of the LED substrates in theabove-described embodiment, the first and the second connectors may bearranged on the outer portion in the radial direction of the LEDsubstrate. When a plurality of pairs, each consisting of a firstconnector and a second connector, are to be provided, some of these ofpairs may be arranged on the inner side in the radial direction of theLED substrates, while others may be arranged on the outer side in theradial direction of the LED substrates.

The feature of the present variation of the invention is described belowas Appendixes.

Appendix 1

An LED lighting apparatus comprising:

-   -   a support plate including a support surface facing an        illumination side which is one side in a first direction;    -   a plurality of LED substrates supported on the support surface        and arranged with respective edges thereof facing each other to        form a ring-like shape as a whole;    -   a plurality of LED chips mounted on each of the LED substrates;    -   a cover that is arranged on the illumination side in the first        direction with respect to the LED substrates and transmits light        from the LED chips;    -   a first connector and a second connector respectively provided        on one and the other of adjacent ones of the LED substrates; and    -   a wiring including a pair of connection ends one of which is        connected to the first connector and the other one of which is        connected to the second connector;    -   wherein the connection ends of the wiring are connected to the        first connector and the second connector in a first connection        direction and a second connection direction, respectively, that        cross a circumferential direction of the LED substrates.

Appendix 2

The LED lighting apparatus as set forth in Appendix 1, wherein the firstand the second connectors are arranged on the LED substrates at portionsclose to edges that are adjacent to each other in the circumferentialdirection.

Appendix 3

The LED lighting apparatus as set forth in Appendix 1 or 2, wherein eachof the first connection direction and the second connection direction isfrom an inner side toward an outer side in a radial direction of the LEDsubstrates.

Appendix 4

The LED lighting apparatus as set forth in Appendix 3, wherein the firstconnector and the second connector are provided on an inner portion ofthe LED substrates in the radial direction.

Appendix 5

The LED lighting apparatus as set forth in Appendix 1 or 2, wherein eachof the first connection direction and the second connection direction isfrom an outer side toward an inner side in the radial direction.

Appendix 6

The LED lighting apparatus as set forth in Appendix 5, wherein the firstconnector and the second connector are provided on an outer portion ofthe LED substrates in the radial direction.

Appendix 7

The LED lighting apparatus as set forth in any one of Appendixes 2-6,wherein the first connection direction and the second connectiondirection are along the radial direction.

Appendix 8

The LED lighting apparatus as set forth in any one of Appendixes 2-6,wherein the first connection direction and the second connectiondirection are parallel to each other or gradually separate from eachother as proceeding forward in the connection directions.

Appendix 9

The LED lighting apparatus as set forth in Appendix 8, wherein the firstconnection direction and the second connection direction form an angleof 90° or less.

Appendix 10

The LED lighting apparatus as set forth in any one of Appendixes 1-9,wherein a plurality of pairs of connectors, each pair consisting of thefirst connector and the second connector, are provided on the LEDsubstrates at portions close to edges that are adjacent to each other inthe circumferential direction.

Appendix 11

The LED lighting apparatus as set forth in Appendix 10, wherein theplurality of pairs of the first and the second connectors include afirst pair and a second pair, the first connector and the secondconnector of the second pair being arranged on an outer side in thecircumferential direction with respect to the first pair.

Appendix 12

The LED lighting apparatus as set forth in Appendix 10 or 11, whereinthe plurality of pairs of the first and the second connectors include athird pair arranged on an outer portion in the radial direction and afourth pair arranged on an inner portion in the radial direction.

Appendix 13

The LED lighting apparatus as set forth in any one of Appendixes 1-12,wherein the support surface or the LED substrates are provided with apositioner for showing an attachment position of each of the LEDsubstrates relative to the support surface.

Appendix 14

The LED lighting apparatus as set forth in Appendix 13, wherein thepositioner includes a cutout formed at an outer periphery of each of theLED substrates and a positioning portion provided in the support surfaceat a position corresponding to the cutout.

Appendix 15

The LED lighting apparatus as set forth in any one of Appendixes 1-14,further comprising:

-   -   an LED accommodating portion in which the plurality of LED        substrates are arranged;    -   a power source accommodating portion positioned on an inner side        in the radial direction with respect to the LED accommodating        portion and accommodating a power source for supplying power to        the LED chips; and    -   a partition that partitions between the LED accommodating        portion and the power source accommodating portion;    -   wherein the partition includes a plurality of through-holes that        provide communication between the LED accommodating portion and        the power source accommodating portion.

Appendix 16

The LED lighting apparatus as set forth in Appendix 15, wherein: thepartition includes a first partition wall and a second partition wallspaced from each other in the radial direction,

-   -   the through-holes include a plurality of first through-holes        formed in the first partition wall and a plurality of second        through-holes formed in the second partition wall, and    -   the first through-holes and the second through-holes are        arranged at positions that do not overlap each other as viewed        in the radial direction.

Appendix 17

The LED lighting apparatus as set forth in Appendix 15 or 16, whereinthe through-holes include:

-   -   a plurality of illumination-side through-holes positioned on the        illumination side in the first direction and arranged in the        circumferential direction; and    -   a plurality of installation-side through-holes positioned on an        installation side opposite from the illumination side in the        first direction and arranged in the circumferential direction.

Appendix 18

The LED lighting apparatus as set forth in any one of Appendixes 15-17,wherein the through-holes account for 30% or less of an area of thepartition.

Appendix 19

The LED lighting apparatus as set forth in any one of Appendixes 15-18,comprising a hollow ring-shaped portion including the partition as partthereof, wherein the power source is arranged in the hollow ring-shapedportion.

Appendix 20

The LED lighting apparatus as set forth in any one of Appendixes 15-19,wherein the power source accommodating portion accommodates therein anadsorbent.

Appendix 21

The LED lighting apparatus as set forth in Appendix 20, wherein theadsorbent includes at least one of zeolite and charcoal powder.

Appendix 22

The LED lighting apparatus as set forth in any one of Appendixes 1-21,comprising a ring-shaped light emitting portion that is arranged on aninner side or an outer side in the radial direction with respect to theLED substrates and emits light from an LED chip.

Appendix 23

The LED lighting apparatus as set forth in Appendix 22, wherein thering-shaped light emitting portion includes a ring-shaped light guidethat transmits light from the LED chip for emission to outside.

1-16. (canceled)
 17. An LED Lighting apparatus comprising: a supportunit formed in an annular shape and having a wall portion which has anangle to a ceiling; and an LED package disposed on a first surface ofthe wall portion of the support unit and outputting light at least in adirection perpendicular to the first surface.
 18. The LED lightingapparatus according to claim 17, further comprising a power sourcesupplying electric power to the LED package, wherein the power source issurrounded by the support unit, and at least partially overlaps with thewall portion in a first direction which is parallel with a surface ofthe ceiling.
 19. The LED lighting apparatus according to claim 17,further comprising a power source supplying the electric power to theLED package, wherein the power source is surrounded by the support unit,and at least partially overlaps with the LED package in a firstdirection which is parallel with a surface of the ceiling.
 20. The LEDlighting apparatus according to claim 18, further comprising aconnecting part to be connected to the ceiling.
 21. The LED lightingapparatus according to claim 20, wherein the connecting part is disposedcloser to the ceiling than the power source is.
 22. The LED lightingapparatus according to claim 20, wherein the connecting part ispositioned between the ceiling and the power source.
 23. The LEDlighting apparatus according to claim 20, wherein at least a part of theconnecting part is surrounded by the support unit, and the connectingpart and the power source at least partially overlap with the wallportion in the first direction.
 24. The LED lighting apparatus accordingto claim 20, wherein at least a part of the connecting part issurrounded by the support unit, and the connecting part and the powersource at least partially overlap with the LED package in the firstdirection.
 25. The LED lighting apparatus according to claim 20, whereinthe connecting part is surrounded by the support unit, and theconnecting pan and the power source at least partially overlap with eachother in the first direction.
 26. The LED lighting apparatus accordingto claim 17, further comprising a first plate formed in an annularshape, wherein the first plate is connected to a proximal edge of thesupport unit to the ceiling, and has a surface which is parallel withthe ceiling.
 27. The LED lighting apparatus according to claim 26,further comprising an inclined portion connected to an edge of the firstplate that is opposite to a center line of the first plate, wherein theinclined portion is inclined so as to become farther from the ceilingwith increasing distance from the center line of the first plate. 28.The LED lighting apparatus according to claim 17, further comprising afirst cover covering the LED package and configured to allow passage ofthe light outputted from the LED package.
 29. The LED lighting apparatusaccording to claim 17, further comprising a base via which the LEDpackage is disposed on the first surface of the will portion.
 30. An LEDLighting apparatus comprising: a first plate; a support unit projectedfrom a surface of the first plate and having a wall portion which is inan annular shape; and an LED package disposed on a surface of the wallportion and outputting light in a direction perpendicular to the surfaceof the wall portion.
 31. The LED lighting apparatus according to claim30, further comprising a power source supplying electric power to theLED package, wherein the power source is surrounded by the support unit,and at least partially overlaps with the wall portion in a firstdirection which is parallel with the surface of the first plate.
 32. TheLED lighting apparatus according to claim 30, further comprising a powersource supplying the electric power to the LED package, wherein thepower source is surrounded by the support unit, and at least partiallyoverlaps with the LED package in a first direction which is parallelwith the surface of the first plate.
 33. The LED lighting apparatusaccording to claim 31, further comprising a connecting part to beconnected to a ceiling.
 34. The LED lighting apparatus according, toclaim 33, wherein the connecting part is disposed closer to the ceilingthan the power source is.
 35. The LED lighting apparatus according toclaim 33, wherein the connecting part is positioned between the ceilingand the power source.
 36. The LED lighting apparatus according to claim33, wherein at least a part of the connecting part is surrounded by thesupport unit, and the connecting part and the power source at leastpartially overlap with the wall portion m the first direction.
 37. TheLED lighting apparatus according to claim 33, wherein at least a part ofthe connecting part is surrounded by the support unit, and theconnecting part and the power source at least partially overlap with theLED package in the first direction.
 38. The LED lighting apparatusaccording to claim 33, wherein the connecting part is surrounded by thesupport unit, and the connecting part and the power source at leastpartially overlap with each other in the first direction.
 39. The LEDlighting apparatus according to claim 30, further comprising an inclinedportion connected to an edge of the first plate that is opposite to acenter line of the first plate, wherein the inclined portion is inclinedso as to become farther from the first plate with increasing distancefrom the center line of the first plate.
 40. The LED lighting apparatusaccording to claim 30, further comprising a first cover covering the LEDpackage and configured to allow passage of the light outputted from theLED package.
 41. The LED lighting apparatus according to claim 30,further comprising a base via which the LED package is disposed on thesurface of the wall portion.